Journal of Changsha University of Science & Technology (Natural Science)
Volume 23,2026 Issue 3
indexed by
- Featured Articles
- Recommended Topics
-
- Detection of earthquake-induced cracks in masonry structures based ondual attention U-Net
- Research on voltage-current characteristics and electrothermal characteristics of multiphase composite conductive asphalt mixtures
- Research on rheological and fatigue properties of ball-milled GNPs/SiO2 composite modified asphalt
- Study on evaporation of Dongting Lake during dry season based on hydrogen and oxygen isotopes
- Current status of resource utilization technologies for dredged sludges in rivers and lakes and their applications
- Research progress of pedestrian-ground contact injuries in pedestrian-vehicle collision accident
- Review of principles and research on noise reduction technology fordense-graded rubber asphalt pavements
-
- Inundation characteristics of typhoon-induced rainfall in Zhuhai based on Sentinel-1A SAR images
- Research progress of real-time acquisition technologies for surrounding rock characteristics of shield tunnels
- Analysis of water level variations during dry season and its impact on water supply of gate-pump system in northern Dongting Lake
- Review on solid hydrogen storage properties and basic improving methods
- Phase change energy storage technology and its application in the integration of transportation and energy
- Current status and prospects of integrated development oftransportation and energy
- Experimental study on mechanical properties of inherent anisotropy sand under pure principal stress rotation
Cover StoryVolume 23,2026 Issue 3
- Current Issue
- Online First
- Archive
- Most Downloaded
Select AllDeselectExport
Display Method:
2026,23(3):1-13
,DOI: 10.19951/j.cnki.1672-9331.20260315001
Abstract:
［Purposes ］ To address the issues of insufficient prediction accuracy and difficulties in engineering application in predicting nonlinear vortex -induced vibration responses of actual bridges，a general modeling framework for nonlinear vortex -induced vibration applicable to typical bridge decks was established.［Methods］ First，based on the nonlinear vortex -induced vibration behavior observed in free -vibration wind tunnel tests，a mathematical model was established，and corresponding methods for parameter identification of the nonlinear model and numerical solution of aeroelastic responses were further developed.The prediction results of the proposed model were then compared with those of the Scanlan empirical nonlinear model and the single -degree -of-freedom vertical simplified model proposed by Zhu et al.Finally，by taking a long -span bridge in its preliminary design stage as an example，a finite element model was established for modal analysis.Three -dimensional vortex -induced vibration analyses were conducted for the first three critical vertical bending modes，and the results were compared with those of the two -dimensional analysis.［Results］ The developed modeling framework for nonlinear vortex -induced vibration has good engineering applicability and prediction accuracy.All of its parameters can be identified solely through free -vibration wind tunnel tests，and the framework accurately predicts the displacement responses of vortex -induced vibration observed in experiments.Compared with the Scanlan empirical nonlinear model and the simplified model proposed by Zhu et al.，this framework exhibits significant advantages in prediction performance.Meanwhile，due to the pronounced three -dimensional spanwise effects of nonlinear vortex -induced forces caused by mode shapes，the vortex -induced vibration amplitudes obtained from three -dimensional analysis are significantly larger than the two -dimensional analysis results.For the first two vertical bending modes，the three -dimensional analysis results are 13.23% and 11.68% greater than the two -dimensional analysis results，respectively.［Conclusions ］ The developed modeling framework for nonlinear vortex -induced vibration offers high prediction accuracy and easy engineering application.Furthermore，it is necessary to fully consider the three -dimensional vortex -induced vibration effects in predicting the vortex -induced vibration responses of bridges.
［Purposes ］ To address the issues of insufficient prediction accuracy and difficulties in engineering application in predicting nonlinear vortex -induced vibration responses of actual bridges，a general modeling framework for nonlinear vortex -induced vibration applicable to typical bridge decks was established.［Methods］ First，based on the nonlinear vortex -induced vibration behavior observed in free -vibration wind tunnel tests，a mathematical model was established，and corresponding methods for parameter identification of the nonlinear model and numerical solution of aeroelastic responses were further developed.The prediction results of the proposed model were then compared with those of the Scanlan empirical nonlinear model and the single -degree -of-freedom vertical simplified model proposed by Zhu et al.Finally，by taking a long -span bridge in its preliminary design stage as an example，a finite element model was established for modal analysis.Three -dimensional vortex -induced vibration analyses were conducted for the first three critical vertical bending modes，and the results were compared with those of the two -dimensional analysis.［Results］ The developed modeling framework for nonlinear vortex -induced vibration has good engineering applicability and prediction accuracy.All of its parameters can be identified solely through free -vibration wind tunnel tests，and the framework accurately predicts the displacement responses of vortex -induced vibration observed in experiments.Compared with the Scanlan empirical nonlinear model and the simplified model proposed by Zhu et al.，this framework exhibits significant advantages in prediction performance.Meanwhile，due to the pronounced three -dimensional spanwise effects of nonlinear vortex -induced forces caused by mode shapes，the vortex -induced vibration amplitudes obtained from three -dimensional analysis are significantly larger than the two -dimensional analysis results.For the first two vertical bending modes，the three -dimensional analysis results are 13.23% and 11.68% greater than the two -dimensional analysis results，respectively.［Conclusions ］ The developed modeling framework for nonlinear vortex -induced vibration offers high prediction accuracy and easy engineering application.Furthermore，it is necessary to fully consider the three -dimensional vortex -induced vibration effects in predicting the vortex -induced vibration responses of bridges.
2026,23(3):14-24
,DOI: 10.19951/j.cnki.1672-9331.20260212001
Abstract:
［Purposes ］ Urban wind field prediction is critical for wind hazard warning，pedestrian comfort assessment，and unmanned aerial vehicle path planning.However，conventional approaches，such as on -site measurements，wind tunnel tests，and computational fluid dynamics （CFD），are time -consuming and expensive.Consequently，these methods are inadequate for large -scale and rapid urban wind field prediction.To address this limitation，this paper proposed a physics -informed data -fusion framework for urban wind field prediction that used sparse multi -site time-series data to forecast urban near -surface wind fields.［Methods］ The framework consists of three modules：a wind -direction inference module that identifies the dominant inflow direction from multi -site wind speed components；a time -series prediction module that utilizes bidirectional long short -term memory （BiLSTM） networks to forecast short -term wind speed components at each site；a physics -informed spatial prediction module that projects the predicted wind speed data onto a two -dimensional grid at the pedestrian level to reconstruct the full -field wind speed components.To enforce physical consistency，the residuals of the incompressible Navier -Stokes equations are incorporated into the training loss function.［Results］ The proposed method is validated using a CFD -generated dataset representing a real urban street environment.The results show that the framework achieves stable full -field prediction accuracy under different wind directions，with an average coefficient of determination for the speed components is approximately 0.80.The framework achieves an order -of-magnitude acceleration compared with CFD.［Conclusions ］ The proposed framework provides an efficient and physically consistent solution for urban wind field prediction from sparse data.
［Purposes ］ Urban wind field prediction is critical for wind hazard warning，pedestrian comfort assessment，and unmanned aerial vehicle path planning.However，conventional approaches，such as on -site measurements，wind tunnel tests，and computational fluid dynamics （CFD），are time -consuming and expensive.Consequently，these methods are inadequate for large -scale and rapid urban wind field prediction.To address this limitation，this paper proposed a physics -informed data -fusion framework for urban wind field prediction that used sparse multi -site time-series data to forecast urban near -surface wind fields.［Methods］ The framework consists of three modules：a wind -direction inference module that identifies the dominant inflow direction from multi -site wind speed components；a time -series prediction module that utilizes bidirectional long short -term memory （BiLSTM） networks to forecast short -term wind speed components at each site；a physics -informed spatial prediction module that projects the predicted wind speed data onto a two -dimensional grid at the pedestrian level to reconstruct the full -field wind speed components.To enforce physical consistency，the residuals of the incompressible Navier -Stokes equations are incorporated into the training loss function.［Results］ The proposed method is validated using a CFD -generated dataset representing a real urban street environment.The results show that the framework achieves stable full -field prediction accuracy under different wind directions，with an average coefficient of determination for the speed components is approximately 0.80.The framework achieves an order -of-magnitude acceleration compared with CFD.［Conclusions ］ The proposed framework provides an efficient and physically consistent solution for urban wind field prediction from sparse data.
2026,23(3):25-35
,DOI: 10.19951/j.cnki.1672-9331.20251201001
Abstract:
［Purposes ］ To improve the aerodynamic performance of vertical -axis wind turbines at low and medium wind speeds，an optimized scheme for a double -layer blade structure was proposed to address the poor starting performance and low wind energy utilization efficiency of conventional single -layer H -type vertical -axis wind turbines.［Methods］ Based on numerical simulation using computational fluid dynamics （CFD），the SST k-ω turbulence model and the sliding mesh method were adopted，and flow -field analysis was used to systematically investigate the effects of longitudinal and transverse offset distances of the small blade relative to the large blade on wind turbine torque，output power，and power coefficient.［Results］ The double -layer blade structure can significantly improve aerodynamic performance at low -to-medium tip speed ratios （1.38-2.19）；the improvement is optimal when the longitudinal offset distance is 0.10 times the rotor radius and the transverse offset distance is 0.40 times the chord length of the large blade.When the tip speed ratio is 1.38，the power coefficient of the double -layer blade structure increases from 0.10 to 0.19 compared with that of the single -layer structure，with a relative increase of up to 90%；flow -field analysis shows that the performance improvement originates from beneficial aerodynamic interference between the large and small blades and their effective control of the wake.In addition，this structure shifts the peak efficiency point toward lower tip speed ratios and broadens the efficient operating range.［Conclusions ］ The double -layer H -type vertical -axis wind turbine proposed in this study can effectively improve starting performance and increase operating efficiency at low wind speeds，providing an important solution approach and theoretical basis for optimizing the aerodynamic performance of vertical -axis wind turbines at low and medium wind speeds.
［Purposes ］ To improve the aerodynamic performance of vertical -axis wind turbines at low and medium wind speeds，an optimized scheme for a double -layer blade structure was proposed to address the poor starting performance and low wind energy utilization efficiency of conventional single -layer H -type vertical -axis wind turbines.［Methods］ Based on numerical simulation using computational fluid dynamics （CFD），the SST k-ω turbulence model and the sliding mesh method were adopted，and flow -field analysis was used to systematically investigate the effects of longitudinal and transverse offset distances of the small blade relative to the large blade on wind turbine torque，output power，and power coefficient.［Results］ The double -layer blade structure can significantly improve aerodynamic performance at low -to-medium tip speed ratios （1.38-2.19）；the improvement is optimal when the longitudinal offset distance is 0.10 times the rotor radius and the transverse offset distance is 0.40 times the chord length of the large blade.When the tip speed ratio is 1.38，the power coefficient of the double -layer blade structure increases from 0.10 to 0.19 compared with that of the single -layer structure，with a relative increase of up to 90%；flow -field analysis shows that the performance improvement originates from beneficial aerodynamic interference between the large and small blades and their effective control of the wake.In addition，this structure shifts the peak efficiency point toward lower tip speed ratios and broadens the efficient operating range.［Conclusions ］ The double -layer H -type vertical -axis wind turbine proposed in this study can effectively improve starting performance and increase operating efficiency at low wind speeds，providing an important solution approach and theoretical basis for optimizing the aerodynamic performance of vertical -axis wind turbines at low and medium wind speeds.
2026,23(3):36-45,71
,DOI: 10.19951/j.cnki.1672-9331.20260112001
Abstract:
［Purposes ］ Accurate determination of the coefficient of earth pressure at rest，K0，is essential for evaluating the resilient modulus of subgrade soil.Considering the combined effects of normal stress，degree of compaction，and water content，this study systematically investigated the nonlinear variation of K0 in subgrade soil，developed a corresponding K0 prediction model，and applied the model to the dynamic response analysis of subgrade structures.［Methods］ Consolidation tests considering multiple influencing factors were conducted using a GJY -type K0 consolidometer.A K0 prediction model was developed with normal stress as the primary variable，while also accounting for soil physical state，including degree of compaction and water content.The reliability of the model was verified through full -scale tests under different combinations of static and dynamic loads.［Results］ （1） K0 initially increases rapidly with increasing normal stress and then tends to stabilize，with an average increase of 65.25%.It decreases with increasing degree of compaction，with an average reduction of 23.43%.Moreover，it increases with increasing water content，with an average increase of 55.1%.（2） The developed power -function K0 prediction model achieves a prediction accuracy of 92%.（3） In the full -scale tests，the model improves the accuracy of resilient deflection prediction by 46% compared with the conventional constant -K0 method.［Conclusions ］ K0 is a parameter that has an upper limit and is affected by the coupled effects of multiple factors.Accounting for its nonlinear characteristics significantly improves the accuracy of dynamic response analysis of subgrade structures.
［Purposes ］ Accurate determination of the coefficient of earth pressure at rest，K0，is essential for evaluating the resilient modulus of subgrade soil.Considering the combined effects of normal stress，degree of compaction，and water content，this study systematically investigated the nonlinear variation of K0 in subgrade soil，developed a corresponding K0 prediction model，and applied the model to the dynamic response analysis of subgrade structures.［Methods］ Consolidation tests considering multiple influencing factors were conducted using a GJY -type K0 consolidometer.A K0 prediction model was developed with normal stress as the primary variable，while also accounting for soil physical state，including degree of compaction and water content.The reliability of the model was verified through full -scale tests under different combinations of static and dynamic loads.［Results］ （1） K0 initially increases rapidly with increasing normal stress and then tends to stabilize，with an average increase of 65.25%.It decreases with increasing degree of compaction，with an average reduction of 23.43%.Moreover，it increases with increasing water content，with an average increase of 55.1%.（2） The developed power -function K0 prediction model achieves a prediction accuracy of 92%.（3） In the full -scale tests，the model improves the accuracy of resilient deflection prediction by 46% compared with the conventional constant -K0 method.［Conclusions ］ K0 is a parameter that has an upper limit and is affected by the coupled effects of multiple factors.Accounting for its nonlinear characteristics significantly improves the accuracy of dynamic response analysis of subgrade structures.
2026,23(3):46-57
,DOI: 10.19951/j.cnki.1672-9331.20260225001
Abstract:
［Purposes ］ This study aims to reveal the cumulative deformation characteristics and bearing degradation mechanism of the tetrapod piled jacket foundation in marine soft clay under long-term horizontal cyclic loads （such as wind and wave actions ） to provide an experimental basis for its design and long -term service performance assessment.［Methods］ Based on a self -developed model test system，laboratory model tests were conducted in saturated soft clay.The entire process of soil disturbance caused by pile penetration and subsequent reconsolidation was completely simulated，and multi -stage static loads and bidirectional cyclic horizontal loads were sequentially applied.By densely arranging strain gauges and displacement sensors on the pile shaft，the variation laws of axial force，bending moment，skin friction，and displacement of the pile shaft with the number of cycles and load level were monitored and obtained in real time.［Results］ Under cyclic loading，the skin friction of the upper pile shaft degrades rapidly with the increase in the number of cycles，while the skin friction of the lower pile section gradually plays a dominant role，and the loaded section continuously moves downward.The bending moment and displacement of the pile shaft are mainly concentrated in the area near the pile top，and the position of the maximum bending moment gradually migrates to the deep part with the increase in the number of cycles.The range of 3-5 times the pile diameter below the mudline is the critical degradation area of the jacket system under cyclic loading.Based on the displacement accumulation law，the response of the jacket can be divided into three stages：stable，critical，and unstable，and its long -term cyclic bearing capacity is approximately 62.5% of its static ultimate bearing capacity.［Conclusions ］ The tetrapod piled jacket foundation exhibits staged degradation characteristics under long -term cyclic loading，and its bearing and deformation performance are jointly controlled by the skin friction degradation of the upper pile shaft and the mobilization of shaft resistance in the lower pile segment.Engineering design should take the long -term cyclic bearing capacity as the main control indicator and focus on the performance evolution within the critical depth range below the mudline.
［Purposes ］ This study aims to reveal the cumulative deformation characteristics and bearing degradation mechanism of the tetrapod piled jacket foundation in marine soft clay under long-term horizontal cyclic loads （such as wind and wave actions ） to provide an experimental basis for its design and long -term service performance assessment.［Methods］ Based on a self -developed model test system，laboratory model tests were conducted in saturated soft clay.The entire process of soil disturbance caused by pile penetration and subsequent reconsolidation was completely simulated，and multi -stage static loads and bidirectional cyclic horizontal loads were sequentially applied.By densely arranging strain gauges and displacement sensors on the pile shaft，the variation laws of axial force，bending moment，skin friction，and displacement of the pile shaft with the number of cycles and load level were monitored and obtained in real time.［Results］ Under cyclic loading，the skin friction of the upper pile shaft degrades rapidly with the increase in the number of cycles，while the skin friction of the lower pile section gradually plays a dominant role，and the loaded section continuously moves downward.The bending moment and displacement of the pile shaft are mainly concentrated in the area near the pile top，and the position of the maximum bending moment gradually migrates to the deep part with the increase in the number of cycles.The range of 3-5 times the pile diameter below the mudline is the critical degradation area of the jacket system under cyclic loading.Based on the displacement accumulation law，the response of the jacket can be divided into three stages：stable，critical，and unstable，and its long -term cyclic bearing capacity is approximately 62.5% of its static ultimate bearing capacity.［Conclusions ］ The tetrapod piled jacket foundation exhibits staged degradation characteristics under long -term cyclic loading，and its bearing and deformation performance are jointly controlled by the skin friction degradation of the upper pile shaft and the mobilization of shaft resistance in the lower pile segment.Engineering design should take the long -term cyclic bearing capacity as the main control indicator and focus on the performance evolution within the critical depth range below the mudline.
2026,23(3):58-71
,DOI: 10.19951/j.cnki.1672-9331.20260225002
Abstract:
［Purposes ］ To investigate the seismic spatial differential effect and its triggering mechanisms of the site soil near the cross -shaped interchange station structure in soft soil areas.［Methods］ A large -scale shaking table test based on an artificial model soil with a scale of 1∶25 was conducted，using Ricker waves with different dominant frequencies as input excitations.A modified elastoplastic single -yield -surface kinematic hardening model was adopted to simulate the soil response，and a three -dimensional full -time-history dynamic numerical model was established，with parameters calibrated using the test results.By synthesizing the test results and numerical calculations，the seismic spatial differential effect of the soft soil near the interchange station was studied，and its triggering mechanisms were explored.［Results］ The interchange station structure has an inhibitory effect on the amplitude propagation amplification of the first predominant frequency of the adjacent stratum，exhibiting significant differential characteristics.The significant differences in stiffness of transfer stations on different axes result in obvious differential response phenomena in the horizontal and vertical directions of the surrounding soil of the interchange station structure under earthquakes.The maximum values of peak ground acceleration at the surface of the soil near the three -story structure all appear within the range of about 0.75-1.00 times the station cross -sectional width outside the structure.［Conclusions ］ The interchange station structure significantly alters the acceleration response of the surrounding soil through the soil-structure interface，and this impact presents obvious spatial difference.When evaluating the seismic safety of urban hub nodes and the seismic fortification of surrounding buildings and structures，especially for integral structures with a span greater than one time the station cross -sectional width，the spatial dynamic response differential effect induced by such large -scale three -dimensional underground structure should be fully considered.
［Purposes ］ To investigate the seismic spatial differential effect and its triggering mechanisms of the site soil near the cross -shaped interchange station structure in soft soil areas.［Methods］ A large -scale shaking table test based on an artificial model soil with a scale of 1∶25 was conducted，using Ricker waves with different dominant frequencies as input excitations.A modified elastoplastic single -yield -surface kinematic hardening model was adopted to simulate the soil response，and a three -dimensional full -time-history dynamic numerical model was established，with parameters calibrated using the test results.By synthesizing the test results and numerical calculations，the seismic spatial differential effect of the soft soil near the interchange station was studied，and its triggering mechanisms were explored.［Results］ The interchange station structure has an inhibitory effect on the amplitude propagation amplification of the first predominant frequency of the adjacent stratum，exhibiting significant differential characteristics.The significant differences in stiffness of transfer stations on different axes result in obvious differential response phenomena in the horizontal and vertical directions of the surrounding soil of the interchange station structure under earthquakes.The maximum values of peak ground acceleration at the surface of the soil near the three -story structure all appear within the range of about 0.75-1.00 times the station cross -sectional width outside the structure.［Conclusions ］ The interchange station structure significantly alters the acceleration response of the surrounding soil through the soil-structure interface，and this impact presents obvious spatial difference.When evaluating the seismic safety of urban hub nodes and the seismic fortification of surrounding buildings and structures，especially for integral structures with a span greater than one time the station cross -sectional width，the spatial dynamic response differential effect induced by such large -scale three -dimensional underground structure should be fully considered.
2026,23(3):72-84
,DOI: 10.19951/j.cnki.1672-9331.20260330001
Abstract:
［Purposes ］ To explore the progressive deterioration mechanism and structural evolution modes of mudstone under dry -wet cycles，a study was conducted based on slope engineering in the Liuyang section of the Changsha -Ganzhou High -Speed Railway.［Methods］ Atmospheric dry -wet cycle simulations were carried out on shallow surface rocks using immersion -drying and dripping -drying test methods.Triaxial tests，along with microscopic tests based on scanning electron microscopy （SEM） equipped with energy dispersive X -ray spectroscopy （EDS） probe，were conducted.［Results］ Macroscopic tests indicate that dry -wet cycles promote crack development，leading to irreversible deterioration in the mechanical properties of mudstone.The cumulative decreases in cohesion and internal friction angle reach 68.4% and 14.8%，respectively.SEM scanning results show that the deterioration of the microstructure is mainly manifested as the disintegration and erosion of the rock matrix.Although the overall rock structure does not exhibit significant swelling or shrinkage，degradation occurs during both dry and wet stages，and the degree of deterioration continuously intensifies with the increase of cycle number.The pore orientation presents periodic oscillation，and the pore morphology expands in a spiral damage mode.In the X -ray diffraction （XRD） test results of minerals，the content of sensitive clay minerals is relatively low，indicating that non -sensitive minerals are the key substances driving the structural deterioration of minerals.EDS results further confirm that dry -wet cycles lead to the weakening or even fracture of calcareous cementations.After dry -wet cycles，the scanning intensity of the Ca element on the surfaces of microscopic samples decreases by 65.3%，while the scanning intensities of Si and O elements remain stable，which provides microscopic support for the macroscopic phenomena.［Conclusions ］ The research results can provide a scientific basis for the instability evolution and safety stability assessment of mudstone slopes.
［Purposes ］ To explore the progressive deterioration mechanism and structural evolution modes of mudstone under dry -wet cycles，a study was conducted based on slope engineering in the Liuyang section of the Changsha -Ganzhou High -Speed Railway.［Methods］ Atmospheric dry -wet cycle simulations were carried out on shallow surface rocks using immersion -drying and dripping -drying test methods.Triaxial tests，along with microscopic tests based on scanning electron microscopy （SEM） equipped with energy dispersive X -ray spectroscopy （EDS） probe，were conducted.［Results］ Macroscopic tests indicate that dry -wet cycles promote crack development，leading to irreversible deterioration in the mechanical properties of mudstone.The cumulative decreases in cohesion and internal friction angle reach 68.4% and 14.8%，respectively.SEM scanning results show that the deterioration of the microstructure is mainly manifested as the disintegration and erosion of the rock matrix.Although the overall rock structure does not exhibit significant swelling or shrinkage，degradation occurs during both dry and wet stages，and the degree of deterioration continuously intensifies with the increase of cycle number.The pore orientation presents periodic oscillation，and the pore morphology expands in a spiral damage mode.In the X -ray diffraction （XRD） test results of minerals，the content of sensitive clay minerals is relatively low，indicating that non -sensitive minerals are the key substances driving the structural deterioration of minerals.EDS results further confirm that dry -wet cycles lead to the weakening or even fracture of calcareous cementations.After dry -wet cycles，the scanning intensity of the Ca element on the surfaces of microscopic samples decreases by 65.3%，while the scanning intensities of Si and O elements remain stable，which provides microscopic support for the macroscopic phenomena.［Conclusions ］ The research results can provide a scientific basis for the instability evolution and safety stability assessment of mudstone slopes.
2026,23(3):85-98
,DOI: 10.19951/j.cnki.1672-9331.20260415001
Abstract:
［Purposes ］ To enhance the targeting of analysis and assessment in high -risk areas，this paper deeply explored the spatial clustering patterns and influencing factors of traffic accident severity and assessed the severity，aiming to provide decision -making guidance for traffic safety management.［Methods］ Based on traffic accident data from Changsha spanning 2017 to 2019，high-value clustering areas of accident severity were identified using average nearest neighbor distance （ANND），Global Moran ’s I，and Local Moran ’s I methods.For samples within these high-value clustering areas，a random parameter Logit model was developed to analyze the influencing factors of accident severity and their unobserved heterogeneity.Then，based on the significant factors，a random forest model was constructed for quantitative assessment.［Results］ Traffic accidents in Changsha showed significant spatial clustering，and the weighted values of accident severity exhibited stable positive spatial autocorrelation.High -value clustering areas were mainly concentrated in the main urban area，with persistent local patches in some suburban areas.The effect of road type on fatal accidents was heterogeneous.Severe accident outcomes were more closely associated with shared lanes （motor and non -motor vehicles ），crosswalks，curve sections，wet pavement，and specific time periods.With potent classification performance，the random forest model was able to provide preliminary discrimination of accident severity.［Conclusions ］ Traffic accident severity displays relatively independent spatial differentiation.In high -risk area identification，accident frequency should not be the only criterion，while the spatial clustering characteristics of accident consequences and their triggering scenarios should also be considered.High -severity accidents are closely associated with the interaction of multiple risk factors，showing certain predictability.
［Purposes ］ To enhance the targeting of analysis and assessment in high -risk areas，this paper deeply explored the spatial clustering patterns and influencing factors of traffic accident severity and assessed the severity，aiming to provide decision -making guidance for traffic safety management.［Methods］ Based on traffic accident data from Changsha spanning 2017 to 2019，high-value clustering areas of accident severity were identified using average nearest neighbor distance （ANND），Global Moran ’s I，and Local Moran ’s I methods.For samples within these high-value clustering areas，a random parameter Logit model was developed to analyze the influencing factors of accident severity and their unobserved heterogeneity.Then，based on the significant factors，a random forest model was constructed for quantitative assessment.［Results］ Traffic accidents in Changsha showed significant spatial clustering，and the weighted values of accident severity exhibited stable positive spatial autocorrelation.High -value clustering areas were mainly concentrated in the main urban area，with persistent local patches in some suburban areas.The effect of road type on fatal accidents was heterogeneous.Severe accident outcomes were more closely associated with shared lanes （motor and non -motor vehicles ），crosswalks，curve sections，wet pavement，and specific time periods.With potent classification performance，the random forest model was able to provide preliminary discrimination of accident severity.［Conclusions ］ Traffic accident severity displays relatively independent spatial differentiation.In high -risk area identification，accident frequency should not be the only criterion，while the spatial clustering characteristics of accident consequences and their triggering scenarios should also be considered.High -severity accidents are closely associated with the interaction of multiple risk factors，showing certain predictability.
2026,23(3):99-111
,DOI: 10.19951/j.cnki.1672-9331.20260209001
Abstract:
［Purposes ］ With the rapid increase in the number of new energy vehicles，the traffic accidents involving them also significantly increase.Traffic accidents are mainly caused by human factors.This study aims to construct a quantitative recognition system for high -risk driving behaviors applicable to new energy vehicles，to promptly identify drivers ’ high -risk driving behaviors and prevent accidents.［Methods］ Firstly，unmanned aerial vehicles were utilized to capture vehicle trajectory videos from high altitudes，and after the extraction and analysis of the videos，a naturalistic driving dataset of new energy vehicles was constructed.Secondly，the characteristic parameter thresholds of three common high -risk driving behaviors，including speeding，abrupt speed change，and dangerous lane -changing，were determined.A high -risk driving behavior spectrum of new energy vehicles was constructed by calculating the characteristic values and conducting a correlation analysis.Then，based on this behavior spectrum，the proportion of high -risk driving behaviors was determined combined with literature and video observation，and the data were balanced by hybrid sampling.Finally，the optimal recognition model was selected by comparing the recognition accuracies of models such as random forest，KNN，support vector machine，XGBoost，and AdaBoost.［Results］ The AdaBoost algorithm based on hybrid sampling is determined as the optimal recognition model，with a precision of 97.6% and a recall of 100.0%，and the AdaBoost algorithm can effectively identify potential high -risk driving behaviors.The analysis of the constructed high -risk driving behavior spectrum shows that the weights of speeding，abrupt speed change，and dangerous lane -changing are 0.401，0.268，and 0.331，respectively，among which speeding behavior has the greatest impact on driving safety.［Conclusions ］ The recognition system constructed in this study can effectively identify the high-risk driving behaviors of new energy vehicles，providing data support and a theoretical foundation for traffic safety management.
［Purposes ］ With the rapid increase in the number of new energy vehicles，the traffic accidents involving them also significantly increase.Traffic accidents are mainly caused by human factors.This study aims to construct a quantitative recognition system for high -risk driving behaviors applicable to new energy vehicles，to promptly identify drivers ’ high -risk driving behaviors and prevent accidents.［Methods］ Firstly，unmanned aerial vehicles were utilized to capture vehicle trajectory videos from high altitudes，and after the extraction and analysis of the videos，a naturalistic driving dataset of new energy vehicles was constructed.Secondly，the characteristic parameter thresholds of three common high -risk driving behaviors，including speeding，abrupt speed change，and dangerous lane -changing，were determined.A high -risk driving behavior spectrum of new energy vehicles was constructed by calculating the characteristic values and conducting a correlation analysis.Then，based on this behavior spectrum，the proportion of high -risk driving behaviors was determined combined with literature and video observation，and the data were balanced by hybrid sampling.Finally，the optimal recognition model was selected by comparing the recognition accuracies of models such as random forest，KNN，support vector machine，XGBoost，and AdaBoost.［Results］ The AdaBoost algorithm based on hybrid sampling is determined as the optimal recognition model，with a precision of 97.6% and a recall of 100.0%，and the AdaBoost algorithm can effectively identify potential high -risk driving behaviors.The analysis of the constructed high -risk driving behavior spectrum shows that the weights of speeding，abrupt speed change，and dangerous lane -changing are 0.401，0.268，and 0.331，respectively，among which speeding behavior has the greatest impact on driving safety.［Conclusions ］ The recognition system constructed in this study can effectively identify the high-risk driving behaviors of new energy vehicles，providing data support and a theoretical foundation for traffic safety management.
2026,23(3):112-121
,DOI: 10.19951/j.cnki.1672-9331.20260328001
Abstract:
［Purposes ］ Three -dimensional （3D） printing enables rapid repair of potholes in asphalt pavements，and the interfacial condition plays a critical role in the performance of the repaired pavements.This paper aimed to investigate the mechanical response of the interface after pothole repair by 3D printing.［Methods］ It proposed a simulation method for the pothole interface and developed a 3D finite -element model of the repaired pavement.It also identified the most unfavorable loading position and investigated the effects of interface configuration，pothole depth，surface radius，interface slope，and material modulus ratio on the interfacial mechanical response in both the traffic and transverse directions.［Results］ When the center of the equivalent circular loaded area coincided with the center of the pothole，the maximum principal stress and maximum shear stress at the interface reached their peak values，representing the most unfavorable loading condition.A smooth pothole interface，where the maximum shear stress in the traffic direction peaked，was more prone to shear failure.The maximum principal stress and maximum shear stress at the interface were both relatively high when the pothole depth was smaller than the thickness of the surface course，especially at depths of 10 mm and 20 mm.The maximum principal stress in the traffic direction tended to zero while the maximum shear stress peaked at a pothole surface radius equal to the radius of the equivalent circular loaded area.Additionally，the shear stress in this direction was 36.2% higher than that in the transverse direction.An interface slope less than 45° had a significant influence on the maximum principal stress and resulted in high maximum shear stresses in both directions.Both the maximum principal stress and maximum shear stress decreased continuously as the modulus ratio of the repair material to the surface course material increased.When the modulus ratio rose from 0.8 to 1.5，the maximum principal stresses in the two directions decreased by 59.6% and 32.7%，respectively.［Conclusions ］ The repair interface is more prone to failure in the traffic direction when the pothole depth is smaller than the thickness of the surface course，the pothole surface radius is close to the radius of the equivalent circular loaded area，and the interface slope is less than 45°.Dedicated design and verification are still required for 3D printing -based pothole repair of asphalt pavements.These findings provide an important theoretical basis for the application of 3D printing to the repair of potholes in asphalt pavements.
［Purposes ］ Three -dimensional （3D） printing enables rapid repair of potholes in asphalt pavements，and the interfacial condition plays a critical role in the performance of the repaired pavements.This paper aimed to investigate the mechanical response of the interface after pothole repair by 3D printing.［Methods］ It proposed a simulation method for the pothole interface and developed a 3D finite -element model of the repaired pavement.It also identified the most unfavorable loading position and investigated the effects of interface configuration，pothole depth，surface radius，interface slope，and material modulus ratio on the interfacial mechanical response in both the traffic and transverse directions.［Results］ When the center of the equivalent circular loaded area coincided with the center of the pothole，the maximum principal stress and maximum shear stress at the interface reached their peak values，representing the most unfavorable loading condition.A smooth pothole interface，where the maximum shear stress in the traffic direction peaked，was more prone to shear failure.The maximum principal stress and maximum shear stress at the interface were both relatively high when the pothole depth was smaller than the thickness of the surface course，especially at depths of 10 mm and 20 mm.The maximum principal stress in the traffic direction tended to zero while the maximum shear stress peaked at a pothole surface radius equal to the radius of the equivalent circular loaded area.Additionally，the shear stress in this direction was 36.2% higher than that in the transverse direction.An interface slope less than 45° had a significant influence on the maximum principal stress and resulted in high maximum shear stresses in both directions.Both the maximum principal stress and maximum shear stress decreased continuously as the modulus ratio of the repair material to the surface course material increased.When the modulus ratio rose from 0.8 to 1.5，the maximum principal stresses in the two directions decreased by 59.6% and 32.7%，respectively.［Conclusions ］ The repair interface is more prone to failure in the traffic direction when the pothole depth is smaller than the thickness of the surface course，the pothole surface radius is close to the radius of the equivalent circular loaded area，and the interface slope is less than 45°.Dedicated design and verification are still required for 3D printing -based pothole repair of asphalt pavements.These findings provide an important theoretical basis for the application of 3D printing to the repair of potholes in asphalt pavements.
2026,23(3):122-134
,DOI: 10.19951/j.cnki.1672-9331.20260131001
Abstract:
Microwave deicing technology has the characteristics of environmental friendliness，low damage，and high clearance efficiency，and it has great promotion value in the field of road snow and ice removal.However，the problem of low microwave deicing efficiency restricts the application of this technology.Traditional cement concrete pavement has low microwave absorption and heating efficiency，resulting in a slow microwave deicing speed.Therefore，researchers have improved the microwave deicing efficiency of concrete by adding wave -absorbing admixtures into concrete，replacing sand and gravel with wave -absorbing aggregates，applying wave -absorbing coatings to the concrete surface，setting wave -absorbing functional layer structures，and improving microwave deicing equipment.The research progress of wave -absorbing admixtures，wave -absorbing aggregates，absorbent wave -absorbing coatings，wave -absorbing functional layers and microwave deicing equipment to improve the efficiency of microwave deicing of concrete at home and abroad was reviewed，and the development of the field of concrete microwave deicing was prospected.There have been many studies on the effect of single wave -absorbing admixtures on the microwave deicing efficiency of concrete；composite wave -absorbing admixtures can achieve dual dielectric -magnetic losses of microwaves.In terms of the proportion in concrete，wave -absorbing aggregates account for a larger share than wave -absorbing admixtures，and their improvement effect on the microwave deicing efficiency of concrete is better.When using wave -absorbing coatings，their impact on the pavement performance of concrete roads should be considered.
Microwave deicing technology has the characteristics of environmental friendliness，low damage，and high clearance efficiency，and it has great promotion value in the field of road snow and ice removal.However，the problem of low microwave deicing efficiency restricts the application of this technology.Traditional cement concrete pavement has low microwave absorption and heating efficiency，resulting in a slow microwave deicing speed.Therefore，researchers have improved the microwave deicing efficiency of concrete by adding wave -absorbing admixtures into concrete，replacing sand and gravel with wave -absorbing aggregates，applying wave -absorbing coatings to the concrete surface，setting wave -absorbing functional layer structures，and improving microwave deicing equipment.The research progress of wave -absorbing admixtures，wave -absorbing aggregates，absorbent wave -absorbing coatings，wave -absorbing functional layers and microwave deicing equipment to improve the efficiency of microwave deicing of concrete at home and abroad was reviewed，and the development of the field of concrete microwave deicing was prospected.There have been many studies on the effect of single wave -absorbing admixtures on the microwave deicing efficiency of concrete；composite wave -absorbing admixtures can achieve dual dielectric -magnetic losses of microwaves.In terms of the proportion in concrete，wave -absorbing aggregates account for a larger share than wave -absorbing admixtures，and their improvement effect on the microwave deicing efficiency of concrete is better.When using wave -absorbing coatings，their impact on the pavement performance of concrete roads should be considered.
2026,23(3):135-148
,DOI: 10.19951/j.cnki.1672-9331.20260326001
Abstract:
［Purposes ］ A multi -scale object detection method was proposed to address the insufficient modeling of object scale and structural variations in unmanned aerial vehicle （UAV） scenarios.［Methods］ A multi -scale representation and modulation network （MRMNet） was constructed.The adaptive spatial multi -scale feature aggregation module （ASMFA） was adopted to enhance the representation of fine -grained and directional features in shallow layers.Meanwhile，the region -driven selective fusion module （RDSFM） was employed to achieve stable cross -scale feature interaction.Additionally，a multi -scale four -head detection structure （MFHD） was designed to strengthen extremely small object detection.［Results］ Compared with the baseline model，MRMNet achieved consistent improvements across multiple datasets.On VisDrone 2019 -DET，mAP 50：95 increased from 16.4% to 19.2%，a rise of 2.8 percentage points，on UAV -PDD 2023，it grew from 51.8% to 62.6%，an increase of 10.8 percentage points，and on UAV -BTCrack，it increased from 27.6% to 28.9%，an increase of 1.3 percentage points.The experimental results demonstrated that the proposed method featured stronger multi -scale modeling and structural representation in complex UAV scenarios.［Conclusions ］ By the coordinated optimization of multi -scale feature representation and fusion mechanisms，MRMNet effectively alleviates the modeling difficulties caused by object scale and structural variations in UAV scenarios，demonstrating superior detection accuracy and strong cross -scenario generalization across multiple UAV vision tasks.
［Purposes ］ A multi -scale object detection method was proposed to address the insufficient modeling of object scale and structural variations in unmanned aerial vehicle （UAV） scenarios.［Methods］ A multi -scale representation and modulation network （MRMNet） was constructed.The adaptive spatial multi -scale feature aggregation module （ASMFA） was adopted to enhance the representation of fine -grained and directional features in shallow layers.Meanwhile，the region -driven selective fusion module （RDSFM） was employed to achieve stable cross -scale feature interaction.Additionally，a multi -scale four -head detection structure （MFHD） was designed to strengthen extremely small object detection.［Results］ Compared with the baseline model，MRMNet achieved consistent improvements across multiple datasets.On VisDrone 2019 -DET，mAP 50：95 increased from 16.4% to 19.2%，a rise of 2.8 percentage points，on UAV -PDD 2023，it grew from 51.8% to 62.6%，an increase of 10.8 percentage points，and on UAV -BTCrack，it increased from 27.6% to 28.9%，an increase of 1.3 percentage points.The experimental results demonstrated that the proposed method featured stronger multi -scale modeling and structural representation in complex UAV scenarios.［Conclusions ］ By the coordinated optimization of multi -scale feature representation and fusion mechanisms，MRMNet effectively alleviates the modeling difficulties caused by object scale and structural variations in UAV scenarios，demonstrating superior detection accuracy and strong cross -scenario generalization across multiple UAV vision tasks.
2026,23(3):149-171
,DOI: 10.19951/j.cnki.1672-9331.20251231001
Abstract:
Landslides induced by tunnel excavation have become increasingly frequent with the rapid advancement of transport infrastructure construction in mountainous areas of China and its extension to areas with high seismic intensity and complex geological structures.Additionally，diseases caused by landslides in built tunnels are becoming increasingly severe.Such issues pose significant threats to the safety of tunnel construction and operation.To systematically promote the study of tunnel -landslide systems，this paper systematically reviewed the current status of research in related fields worldwide.Specifically，it reviewed the research status and history of the tunnel -landslide system and divided the research history into two stages：studies of unidirectional disaster -inducing mechanisms and systematic interaction investigations.Then，it summarized the classification of tunnel -landslide systems and systematically examined the influences of various external factors on the stability of the systems.Furthermore，this paper analyzed the stress and deformation characteristics of tunnels under different spatial configurations and identified the limitations of existing calculation methods for surrounding rocks.Finally，it summarized the currently available disaster prevention and control technologies and continued to point out the deficiencies in the current research and the areas requiring further investigation.it also proposed that future research should further explore the interaction mechanism of tunnel -landslide systems under the coupling of multiple factors，especially the influence of seismic dynamic loading.On this basis，efforts should also be made to establish collaborative treatment criteria centered on deformation compatibility and failure correlation，actively promote the application of new technologies，materials，and processes，and build more universal theoretical models and disaster prevention and control systems.
Landslides induced by tunnel excavation have become increasingly frequent with the rapid advancement of transport infrastructure construction in mountainous areas of China and its extension to areas with high seismic intensity and complex geological structures.Additionally，diseases caused by landslides in built tunnels are becoming increasingly severe.Such issues pose significant threats to the safety of tunnel construction and operation.To systematically promote the study of tunnel -landslide systems，this paper systematically reviewed the current status of research in related fields worldwide.Specifically，it reviewed the research status and history of the tunnel -landslide system and divided the research history into two stages：studies of unidirectional disaster -inducing mechanisms and systematic interaction investigations.Then，it summarized the classification of tunnel -landslide systems and systematically examined the influences of various external factors on the stability of the systems.Furthermore，this paper analyzed the stress and deformation characteristics of tunnels under different spatial configurations and identified the limitations of existing calculation methods for surrounding rocks.Finally，it summarized the currently available disaster prevention and control technologies and continued to point out the deficiencies in the current research and the areas requiring further investigation.it also proposed that future research should further explore the interaction mechanism of tunnel -landslide systems under the coupling of multiple factors，especially the influence of seismic dynamic loading.On this basis，efforts should also be made to establish collaborative treatment criteria centered on deformation compatibility and failure correlation，actively promote the application of new technologies，materials，and processes，and build more universal theoretical models and disaster prevention and control systems.
2026,23(3):172-183
,DOI: 10.19951/j.cnki.1672-9331.20260118001
Abstract:
［Purposes ］ The rapid construction of large -section shafts is crucial for multi -face tunneling operations and subsequent ventilation management in subsea tunnel construction.To ensure the stability of shaft construction，overcome the limitations of short excavation and support segment heights and slow construction in traditional shaft construction technologies，and achieve the rapid construction of large -section shafts，this paper took the Huangdao terminal shaft project of the Second Subsea Tunnel in Jiaozhou Bay，Qingdao City as the background，focused on the shaft construction technology，and improved the construction efficiency by adjusting the construction segment height to achieve rapid shaft construction.［Methods］ This paper used PLAXIS 3D software to simulate the shaft construction.Based on the numerical simulation and field monitoring results，as well as considerations of safety and engineering experience，the original construction segment heights were optimized：The single excavation segment height was increased from 1 m to 6 m，and the secondary lining construction segment height was adjusted to more than 10 m.［Results］ After adopting the optimized construction technology，the overall construction period is shortened by two months；the displacement convergence of the surrounding rock of the shaft increases with the increase of construction depth，and the maximum convergence value of the surrounding rock occurs at the bottom surface of the completed excavation section.The influence range of the horizontal displacement of the surrounding rock is limited.When the construction reaches the connection area of different rock stratum grades and the area where the joint development zone is located，the strength of the surrounding rock is low，and the stability is poor，resulting in a larger displacement convergence and fluctuation amplitude at these locations.The force and displacement of the anchor rods reach a dynamic coupling with the displacement of the surrounding rock and the construction depth，and there is a phenomenon of excessively high safety redundancy of the anchor rods.When a single excavation segment height of 6 m and a secondary lining construction segment height of 10-20 m are adopted，the maximum horizontal displacement convergence values of the shaft obtained by simulation and monitoring are 10.1 mm and 16.4 mm，respectively，both of which are less than the warning value of 30 mm.［Conclusions ］ Under the condition of good rock stratum stability，the construction rate of subsea tunnel shafts can be improved by optimizing the single excavation and support segment height and the secondary lining construction segment height，so as to achieve the effect of rapid shaft construction.At the same time，considering safety，economy，and other factors，the single excavation and support segment height should be controlled at about 6 m，and the secondary lining construction segment height should be controlled within 20 m.In addition，the spacing of the upper anchor rods can be appropriately increased，and the spacing of the lower anchor rods can be correspondingly reduced according to the actual situation to ensure the stability of the surrounding rock and the construction economy.
［Purposes ］ The rapid construction of large -section shafts is crucial for multi -face tunneling operations and subsequent ventilation management in subsea tunnel construction.To ensure the stability of shaft construction，overcome the limitations of short excavation and support segment heights and slow construction in traditional shaft construction technologies，and achieve the rapid construction of large -section shafts，this paper took the Huangdao terminal shaft project of the Second Subsea Tunnel in Jiaozhou Bay，Qingdao City as the background，focused on the shaft construction technology，and improved the construction efficiency by adjusting the construction segment height to achieve rapid shaft construction.［Methods］ This paper used PLAXIS 3D software to simulate the shaft construction.Based on the numerical simulation and field monitoring results，as well as considerations of safety and engineering experience，the original construction segment heights were optimized：The single excavation segment height was increased from 1 m to 6 m，and the secondary lining construction segment height was adjusted to more than 10 m.［Results］ After adopting the optimized construction technology，the overall construction period is shortened by two months；the displacement convergence of the surrounding rock of the shaft increases with the increase of construction depth，and the maximum convergence value of the surrounding rock occurs at the bottom surface of the completed excavation section.The influence range of the horizontal displacement of the surrounding rock is limited.When the construction reaches the connection area of different rock stratum grades and the area where the joint development zone is located，the strength of the surrounding rock is low，and the stability is poor，resulting in a larger displacement convergence and fluctuation amplitude at these locations.The force and displacement of the anchor rods reach a dynamic coupling with the displacement of the surrounding rock and the construction depth，and there is a phenomenon of excessively high safety redundancy of the anchor rods.When a single excavation segment height of 6 m and a secondary lining construction segment height of 10-20 m are adopted，the maximum horizontal displacement convergence values of the shaft obtained by simulation and monitoring are 10.1 mm and 16.4 mm，respectively，both of which are less than the warning value of 30 mm.［Conclusions ］ Under the condition of good rock stratum stability，the construction rate of subsea tunnel shafts can be improved by optimizing the single excavation and support segment height and the secondary lining construction segment height，so as to achieve the effect of rapid shaft construction.At the same time，considering safety，economy，and other factors，the single excavation and support segment height should be controlled at about 6 m，and the secondary lining construction segment height should be controlled within 20 m.In addition，the spacing of the upper anchor rods can be appropriately increased，and the spacing of the lower anchor rods can be correspondingly reduced according to the actual situation to ensure the stability of the surrounding rock and the construction economy.
2026,23(3):184-194
,DOI: 10.19951/j.cnki.1672-9331.20260212002
Abstract:
［Purposes ］ Drag -reducing slurry plays a key lubricating role in pipe jacking construction，and the slurry sleeve thickness is a key indicator determining the drag reduction and lubrication effect.In the actual pipe jacking construction process，the thickness of the slurry sleeve changes longitudinally and becomes thinner as the slurry pressure gradient decays.Therefore，the frictional resistance in the pipe jacking construction process varies dynamically.However，traditional calculation methods for frictional resistance in pipe jacking do not consider the thickness variation of the slurry sleeve and assume the frictional resistance to be ideal and constant，leading to a large deviation between the calculation results and the measured data.［Methods］ Focusing on the calculation of slurry sleeve thickness at various stages of the pipe jacking construction process，the semi -infinite space cylindrical hole expansion theory in elastic mechanics and the flat -plate model theory in viscous fluid mechanics were respectively adopted.Meanwhile，the slurry pressure and its pressure drop ratio were used to establish the calculation methods of the drag -reducing slurry sleeve thickness and its longitudinal variation in the grouting stage and the pipe jacking stage.Furthermore，combining the different contact states between the jacking pipe and the hole wall，and according to the basic formula of pipe -slurry -soil frictional resistance，the calculation formula of dynamic frictional resistance in pipe jacking considering the longitudinal attenuation of slurry sleeve thickness was derived.［Results］ The predicted values of pipe jacking frictional resistance by the proposed method agree well with the measured values，and the relative error between them is about 3.0%；compared with the German empirical formula，the Beijing empirical formula，and Yang Linde ’s formula，this method shows higher calculation accuracy.The calculation results of the dynamic frictional resistance in pipe jacking considering the longitudinal attenuation of the slurry sleeve thickness are basically consistent with the change trend of the measured dynamic frictional resistance in the jacking process.［Conclusions ］ This research has important scientific significance and engineering value for accurately predicting the jacking force and drag reduction loss in pipe jacking projects.
［Purposes ］ Drag -reducing slurry plays a key lubricating role in pipe jacking construction，and the slurry sleeve thickness is a key indicator determining the drag reduction and lubrication effect.In the actual pipe jacking construction process，the thickness of the slurry sleeve changes longitudinally and becomes thinner as the slurry pressure gradient decays.Therefore，the frictional resistance in the pipe jacking construction process varies dynamically.However，traditional calculation methods for frictional resistance in pipe jacking do not consider the thickness variation of the slurry sleeve and assume the frictional resistance to be ideal and constant，leading to a large deviation between the calculation results and the measured data.［Methods］ Focusing on the calculation of slurry sleeve thickness at various stages of the pipe jacking construction process，the semi -infinite space cylindrical hole expansion theory in elastic mechanics and the flat -plate model theory in viscous fluid mechanics were respectively adopted.Meanwhile，the slurry pressure and its pressure drop ratio were used to establish the calculation methods of the drag -reducing slurry sleeve thickness and its longitudinal variation in the grouting stage and the pipe jacking stage.Furthermore，combining the different contact states between the jacking pipe and the hole wall，and according to the basic formula of pipe -slurry -soil frictional resistance，the calculation formula of dynamic frictional resistance in pipe jacking considering the longitudinal attenuation of slurry sleeve thickness was derived.［Results］ The predicted values of pipe jacking frictional resistance by the proposed method agree well with the measured values，and the relative error between them is about 3.0%；compared with the German empirical formula，the Beijing empirical formula，and Yang Linde ’s formula，this method shows higher calculation accuracy.The calculation results of the dynamic frictional resistance in pipe jacking considering the longitudinal attenuation of the slurry sleeve thickness are basically consistent with the change trend of the measured dynamic frictional resistance in the jacking process.［Conclusions ］ This research has important scientific significance and engineering value for accurately predicting the jacking force and drag reduction loss in pipe jacking projects.
Select AllDeselectExport
Display Method:
Select AllDeselectExport
Display Method:
2026,23(2):152-165
,DOI: 10.19951/j.cnki.1672-9331.20260131002
Abstract:
With the rapid development of the low -altitude economy，collaborative delivery involving unmanned aerial vehicles and ground vehicles has emerged as a promising approach to alleviating the “last-kilometer ” bottleneck in logistics.This paper systematically reviews the conceptual definitions，typical application scenarios，and operational modes of air -ground collaborative delivery systems，and argues that the three -dimensional coupling of time，space，and task constitutes the fundamental characteristic of such problems.Air-ground collaborative delivery systems can be classified into three operational modes：vehicle -mounted takeoff and landing，fixed handover points，and dynamic rendezvous.Correspondingly，the modeling framework has evolved through four levels，from mechanism -based benchmark models to dynamic and robust models.Solution methods have also shifted from exact approaches to hybrid optimization frameworks centered on feasibility assurance，integrating mathematical decomposition，metaheuristics，and learning -driven methods.Current research still faces several challenges，including insufficient endogenization of airspace regulatory constraints，limited adaptability to complex environments，and weak engineering deployability.Future research should promote the transition of air -ground collaborative delivery systems from theoretical optimality to stable and operationally viable deployment through hierarchical integrated modeling，endogenous representation of capacity and congestion effects，and the development of robust and online optimization mechanisms，thereby supporting their large -scale and sustainable application.
With the rapid development of the low -altitude economy，collaborative delivery involving unmanned aerial vehicles and ground vehicles has emerged as a promising approach to alleviating the “last-kilometer ” bottleneck in logistics.This paper systematically reviews the conceptual definitions，typical application scenarios，and operational modes of air -ground collaborative delivery systems，and argues that the three -dimensional coupling of time，space，and task constitutes the fundamental characteristic of such problems.Air-ground collaborative delivery systems can be classified into three operational modes：vehicle -mounted takeoff and landing，fixed handover points，and dynamic rendezvous.Correspondingly，the modeling framework has evolved through four levels，from mechanism -based benchmark models to dynamic and robust models.Solution methods have also shifted from exact approaches to hybrid optimization frameworks centered on feasibility assurance，integrating mathematical decomposition，metaheuristics，and learning -driven methods.Current research still faces several challenges，including insufficient endogenization of airspace regulatory constraints，limited adaptability to complex environments，and weak engineering deployability.Future research should promote the transition of air -ground collaborative delivery systems from theoretical optimality to stable and operationally viable deployment through hierarchical integrated modeling，endogenous representation of capacity and congestion effects，and the development of robust and online optimization mechanisms，thereby supporting their large -scale and sustainable application.
2026,23(2):166-176
,DOI: 10.19951/j.cnki.1672-9331.20250917001
Abstract:
［Purposes ］ The rapid development of automated vehicles （AVs） improves traffic safety potential，but it also brings about new interaction risks in human -machine mixed traffic environments，one of which is the risk of bullying behavior by human -driven vehicles （HDVs） toward AVs.Existing studies mostly focus on the external manifestations of bullying behavior and lack in -depth exploration of the psychological mechanisms.Therefore，this paper aims to analyze the psychological and cognitive pathways of HDV drivers ’ intention to bully AVs and evaluate the effectiveness of vehicle -to-vehicle （V2V） communication technology as an intervention measure.［Methods］ Based on the theory of planned behavior （TPB），a psychological model of bullying behavior including attitudes，subjective norms，and perceived behavioral control was constructed，and V 2V information interaction was introduced as an external intervention variable.Unsignalized intersections were selected as the typical scenarios，and a questionnaire survey was conducted among drivers in Changsha，China （valid sample size N = 407）.A structural equation model （SEM） was employed for hypothesis testing and path analysis.［Results］ The model fits well.The results indicate that perceived behavioral control，subjective norms，and attitudes all have a significant impact on bullying intention；younger drivers and those with longer driving experience show a stronger tendency to bully；V2V communication technology can effectively suppress bullying intention，and the effect is more significant among female，older，and highly experienced drivers.［Conclusions ］ A psychological mechanism model of HDV drivers ’ bullying behavior toward AVs under the TPB framework is innovatively constructed and validated in this paper.V2V communication technology is incorporated into the analysis as a behavioral intervention variable，which provides an empirical basis for AV human -machine interaction design and targeted prevention and control strategies.
［Purposes ］ The rapid development of automated vehicles （AVs） improves traffic safety potential，but it also brings about new interaction risks in human -machine mixed traffic environments，one of which is the risk of bullying behavior by human -driven vehicles （HDVs） toward AVs.Existing studies mostly focus on the external manifestations of bullying behavior and lack in -depth exploration of the psychological mechanisms.Therefore，this paper aims to analyze the psychological and cognitive pathways of HDV drivers ’ intention to bully AVs and evaluate the effectiveness of vehicle -to-vehicle （V2V） communication technology as an intervention measure.［Methods］ Based on the theory of planned behavior （TPB），a psychological model of bullying behavior including attitudes，subjective norms，and perceived behavioral control was constructed，and V 2V information interaction was introduced as an external intervention variable.Unsignalized intersections were selected as the typical scenarios，and a questionnaire survey was conducted among drivers in Changsha，China （valid sample size N = 407）.A structural equation model （SEM） was employed for hypothesis testing and path analysis.［Results］ The model fits well.The results indicate that perceived behavioral control，subjective norms，and attitudes all have a significant impact on bullying intention；younger drivers and those with longer driving experience show a stronger tendency to bully；V2V communication technology can effectively suppress bullying intention，and the effect is more significant among female，older，and highly experienced drivers.［Conclusions ］ A psychological mechanism model of HDV drivers ’ bullying behavior toward AVs under the TPB framework is innovatively constructed and validated in this paper.V2V communication technology is incorporated into the analysis as a behavioral intervention variable，which provides an empirical basis for AV human -machine interaction design and targeted prevention and control strategies.
2022,19(4):55-63
,DOI: 10.19951/j.cnki.1672?9331.2022.04.006
Abstract:
[Purposes] The paper aims to figure out the development regulation and anisotropy of mechanical properties of 3D printed slag?fly ash?based geopolymer concrete with age. [Methods] The cubic compressive strength, axial compressive strength and flexural strength of printed geopolymer concrete at different curing ages and along x, y and z loading directions were tested in this study. X?ray CT scanner was used to analyze the microstructure and clarify the influence mechanism on the mechanical properties of printed concrete. [Findings] The mechanical strengths of printed concretes at 3 and 7 d were more 30% and 60% than that at 28 d, respectively. The printed concrete had an early strength and met the requirement of concrete printing construction. The differences in cubic compressive strength, axial compressive strength and flexural strength of the specimens cured for 28 d in each loading direction were in the range of 3.20%-10.40%, 1.53%-7.05% and 5.10%-24.00%, respectively. [Conclusions] The printed concrete exhibited certain anisotropy in mechanical performance, mainly due to the number and spatial distribution of defects in the material during the stacking process of the printed concrete.
[Purposes] The paper aims to figure out the development regulation and anisotropy of mechanical properties of 3D printed slag?fly ash?based geopolymer concrete with age. [Methods] The cubic compressive strength, axial compressive strength and flexural strength of printed geopolymer concrete at different curing ages and along x, y and z loading directions were tested in this study. X?ray CT scanner was used to analyze the microstructure and clarify the influence mechanism on the mechanical properties of printed concrete. [Findings] The mechanical strengths of printed concretes at 3 and 7 d were more 30% and 60% than that at 28 d, respectively. The printed concrete had an early strength and met the requirement of concrete printing construction. The differences in cubic compressive strength, axial compressive strength and flexural strength of the specimens cured for 28 d in each loading direction were in the range of 3.20%-10.40%, 1.53%-7.05% and 5.10%-24.00%, respectively. [Conclusions] The printed concrete exhibited certain anisotropy in mechanical performance, mainly due to the number and spatial distribution of defects in the material during the stacking process of the printed concrete.
Estimation of adsorbed nitrogen and phosphorus load in Datong Lake Basin based on soil loss equation
2023,20(4):64-75
,DOI: 10.19951/j.cnki.1672-9331.20221124001
Abstract:
[Purposes] The water quality of Datong Lake has been in Class three or below for a long time, and the main pollutants exceeding the standard are total nitrogen and total phosphorus. By estimating pollution loads of absorbed nitrogen and phosphorus in Datong Lake basin, it provides a scientific basis for water environment management and protection in Datong Lake area. [Methods] The study used the modified general soil erosion equation, coupled with the adsorbed nitrogen and phosphorus pollution loads model to estimate the adsorbed nitrogen and phosphorus pollution loads in the study area, focusing on analyzing the spatial distribution characteristics of adsorbed nitrogen and phosphorus pollution in the Datong Lake Basin. [Findings] The model calculation results showed that in 2020, the total soil erosion in Datong Lake Basin was 4804.8 t, the average soil erosion modulus was 5.20 t/(km2·a), the adsorption nitrogen and phosphorus loads were 4.943 t and 2.098 t, respectively. According to the adsorbed nitrogen and phosphorus pollution load modulus of each land use type in the basin, the order from large to small is: forest land, cultivated land, construction land. According to the administrative area, Maocaojie, Qingshuzui, Wuzui, Mingshandou and Heba Town adsorbed nitrogen and phosphorus pollution were more serious; The load of nitrogen and phosphorus pollution in the Wuqi Canal basin, the Suhe River basin, the Daxin River basin, the Datong Lake West into the lake area, and the Caoyang Canal area are larger. [Conclusions] The soil erosion intensity in the Datong Lake basin is mainly slight erosion, and cultivated land is the main source of adsorbed nitrogen and phosphorus loss. For areas with large loss of adsorbed nitrogen and phosphorus, it can be controlled according to the ideas of source reduction, process interception, and end-treatment. At the same time, the agricultural planting structure should be adjusted appropriately, the farming methods should be improved, and the soil and water conservation measures should be improved to reduce the soil loss and reduce the direct impact of adsorbed nitrogen and phosphorus pollutants on the water bodies.
[Purposes] The water quality of Datong Lake has been in Class three or below for a long time, and the main pollutants exceeding the standard are total nitrogen and total phosphorus. By estimating pollution loads of absorbed nitrogen and phosphorus in Datong Lake basin, it provides a scientific basis for water environment management and protection in Datong Lake area. [Methods] The study used the modified general soil erosion equation, coupled with the adsorbed nitrogen and phosphorus pollution loads model to estimate the adsorbed nitrogen and phosphorus pollution loads in the study area, focusing on analyzing the spatial distribution characteristics of adsorbed nitrogen and phosphorus pollution in the Datong Lake Basin. [Findings] The model calculation results showed that in 2020, the total soil erosion in Datong Lake Basin was 4804.8 t, the average soil erosion modulus was 5.20 t/(km2·a), the adsorption nitrogen and phosphorus loads were 4.943 t and 2.098 t, respectively. According to the adsorbed nitrogen and phosphorus pollution load modulus of each land use type in the basin, the order from large to small is: forest land, cultivated land, construction land. According to the administrative area, Maocaojie, Qingshuzui, Wuzui, Mingshandou and Heba Town adsorbed nitrogen and phosphorus pollution were more serious; The load of nitrogen and phosphorus pollution in the Wuqi Canal basin, the Suhe River basin, the Daxin River basin, the Datong Lake West into the lake area, and the Caoyang Canal area are larger. [Conclusions] The soil erosion intensity in the Datong Lake basin is mainly slight erosion, and cultivated land is the main source of adsorbed nitrogen and phosphorus loss. For areas with large loss of adsorbed nitrogen and phosphorus, it can be controlled according to the ideas of source reduction, process interception, and end-treatment. At the same time, the agricultural planting structure should be adjusted appropriately, the farming methods should be improved, and the soil and water conservation measures should be improved to reduce the soil loss and reduce the direct impact of adsorbed nitrogen and phosphorus pollutants on the water bodies.
2022,19(3):69-77
,DOI: 10.19951/j.cnki.1672-9331.2022.03.007
Abstract:
［Purposes］ The paper aims to study the deformation evolution law of the excavation of huge deep foundation pits in complex environments and optimize the design of support structures.［Methods］ Based on the foundation pit engineering of Guangzhou Metro Line 11, the variation laws of the horizontal displacement of support structures and the surface settlement of the surrounding soil were studied by using the finite-difference software FLAC3D in the foundation pit excavation project. By analyzing the influence of the embedded depth, the thickness of the diaphragm wall, and the number of layers of support structure on the deformation of the foundation pit, the support structure of the foundation pit was optimized. The support effect before and after the optimization of the support structure was compared and analyzed.［Findings］ Under different operating conditions, the surface settlement of the surrounding soil first increases and then decreases, and the largest settlement occurs at the position of 15.0 m from the edge of the foundation pit; Under different embedded depths, the variation trends of the horizontal displacement of diaphragm wall and the surface settlement of surrounding soil are basically the same; The change of the thickness of diaphragm wall has no obvious effect on its horizontal displacement and surface settlement; The increase of the number of support layers can significantly reduce the horizontal displacement of the support structure and the maximal settlement of the surrounding soil. After the optimization of support structures, the maximal settlement of the surrounding soil is reduced by 23.88%, and the maximal horizontal displacement of diaphragm wall is reduced by 1919%.［Conclusions］ In the design of the same type of foundation pit, attention should be paid to the selection of the number of support layers. The thickness of support structure can be appropriately reduced if necessary.
［Purposes］ The paper aims to study the deformation evolution law of the excavation of huge deep foundation pits in complex environments and optimize the design of support structures.［Methods］ Based on the foundation pit engineering of Guangzhou Metro Line 11, the variation laws of the horizontal displacement of support structures and the surface settlement of the surrounding soil were studied by using the finite-difference software FLAC3D in the foundation pit excavation project. By analyzing the influence of the embedded depth, the thickness of the diaphragm wall, and the number of layers of support structure on the deformation of the foundation pit, the support structure of the foundation pit was optimized. The support effect before and after the optimization of the support structure was compared and analyzed.［Findings］ Under different operating conditions, the surface settlement of the surrounding soil first increases and then decreases, and the largest settlement occurs at the position of 15.0 m from the edge of the foundation pit; Under different embedded depths, the variation trends of the horizontal displacement of diaphragm wall and the surface settlement of surrounding soil are basically the same; The change of the thickness of diaphragm wall has no obvious effect on its horizontal displacement and surface settlement; The increase of the number of support layers can significantly reduce the horizontal displacement of the support structure and the maximal settlement of the surrounding soil. After the optimization of support structures, the maximal settlement of the surrounding soil is reduced by 23.88%, and the maximal horizontal displacement of diaphragm wall is reduced by 1919%.［Conclusions］ In the design of the same type of foundation pit, attention should be paid to the selection of the number of support layers. The thickness of support structure can be appropriately reduced if necessary.
2023,20(2):10-26
,DOI: 10.19951/j.cnki.1672-9331.20221214001
Abstract:
[Purposes] This study aims at directing the condition-based maintenance of equipment by expounding the connotation of complex equipment fault prognostic. [Methods] In this study, the relevant research contents, status, and methods were investigated, summarized, and analyzed. The existing fault prognostic methods were divided into different categories and the corresponding application conditions, advantages, and drawbacks were discussed. [Findings] The knowledge-based methods can take full advantage of the experiential knowledge from experts, but the knowledge acquisition was a bottleneck problem. The model-based methods had the advantages of in-depth understanding of the nature of the target systems, but it was difficult to establish accurate models for complex equipments. The data-driven methods relied on a large amount of data. However, the cost of acquiring typical data of some complex equipments was very high. The hybrid methods can overcome the limitation of a single method, but designing an effective hybrid model was challenging. [Conclusions] The hybrid methods can improve the intelligence and performance of the fault prognostic system, which is an important development trend of complex equipment falt prognostic.
[Purposes] This study aims at directing the condition-based maintenance of equipment by expounding the connotation of complex equipment fault prognostic. [Methods] In this study, the relevant research contents, status, and methods were investigated, summarized, and analyzed. The existing fault prognostic methods were divided into different categories and the corresponding application conditions, advantages, and drawbacks were discussed. [Findings] The knowledge-based methods can take full advantage of the experiential knowledge from experts, but the knowledge acquisition was a bottleneck problem. The model-based methods had the advantages of in-depth understanding of the nature of the target systems, but it was difficult to establish accurate models for complex equipments. The data-driven methods relied on a large amount of data. However, the cost of acquiring typical data of some complex equipments was very high. The hybrid methods can overcome the limitation of a single method, but designing an effective hybrid model was challenging. [Conclusions] The hybrid methods can improve the intelligence and performance of the fault prognostic system, which is an important development trend of complex equipment falt prognostic.
2021,18(1):7-15
,DOI: 10.19951/j.cnki.cslgdxxbzkb.2021.01.002
Abstract:
The existing safety risk identification methods of subway tunnel construction lack certain systematicness,and lack multiimensional risk scenario identification in the risk identification process, so they have certain limitation. Based on the hierarchical holographic modeling (HHM) method,risk filtering,ranking and management(RFRM)framework and scenario analysis theory,a HHM method for identifying risk scenarios in subway tunnel construction was constructed. The risk scenarios were identified from multiple perspectives, and were filtered and sorted by the RFRM framework four-times to screen the keyrisk scenarios. The case study of a subway tunnel project in C City shows that the method can systematically and perfectly identify the safety risk scenarios and keyrisk factors of subway tunnel construction, and further layscertain foundation for risk management.
The existing safety risk identification methods of subway tunnel construction lack certain systematicness,and lack multiimensional risk scenario identification in the risk identification process, so they have certain limitation. Based on the hierarchical holographic modeling (HHM) method,risk filtering,ranking and management(RFRM)framework and scenario analysis theory,a HHM method for identifying risk scenarios in subway tunnel construction was constructed. The risk scenarios were identified from multiple perspectives, and were filtered and sorted by the RFRM framework four-times to screen the keyrisk scenarios. The case study of a subway tunnel project in C City shows that the method can systematically and perfectly identify the safety risk scenarios and keyrisk factors of subway tunnel construction, and further layscertain foundation for risk management.
2024,21(1):59-87
,DOI: 10.19951/j.cnki.1672-9331.20231225001
Abstract:
The subgrade is the main load-bearing structure of highways. With the transition of China′s highway construction from high-speed development to high-quality development, digital construction technology, intelligent construction, and information management have become the core technical means in subgrade engineering. This paper summarizes the research status of key technologies of construction and maintenance for intelligent highway subgrades, mainly analyzing building information modeling (BIM) technology, intelligent compaction technology for subgrades, subgrade health monitoring and assessment technology, and intelligent grouting reinforcement technology for subgrades. The current problems are as follows: the application of BIM technology in the field of subgrade engineering is still in its infancy, lacking reasonable construction quality quantification indicators and cost estimation methods. The theoretical research on intelligent compaction technology is weak, and there is limited research on quality uniformity evaluation. Existing measurement methods for subgrade monitoring and assessment technology are susceptible to interference from other factors and require significant human intervention. In addition, there is no unified quality evaluation index for grouting reinforcement technology, mostly relying on engineering experience and theoretical analysis for evaluation. Therefore, it is necessary to conduct intelligent theoretical and applied research on various key technologies to address the proposed problems and provide guidance for the intelligent construction and maintenance of subgrade engineering in the future.
The subgrade is the main load-bearing structure of highways. With the transition of China′s highway construction from high-speed development to high-quality development, digital construction technology, intelligent construction, and information management have become the core technical means in subgrade engineering. This paper summarizes the research status of key technologies of construction and maintenance for intelligent highway subgrades, mainly analyzing building information modeling (BIM) technology, intelligent compaction technology for subgrades, subgrade health monitoring and assessment technology, and intelligent grouting reinforcement technology for subgrades. The current problems are as follows: the application of BIM technology in the field of subgrade engineering is still in its infancy, lacking reasonable construction quality quantification indicators and cost estimation methods. The theoretical research on intelligent compaction technology is weak, and there is limited research on quality uniformity evaluation. Existing measurement methods for subgrade monitoring and assessment technology are susceptible to interference from other factors and require significant human intervention. In addition, there is no unified quality evaluation index for grouting reinforcement technology, mostly relying on engineering experience and theoretical analysis for evaluation. Therefore, it is necessary to conduct intelligent theoretical and applied research on various key technologies to address the proposed problems and provide guidance for the intelligent construction and maintenance of subgrade engineering in the future.
2019(1):66-72
Abstract:
In order to study the pressure characteristics of the underwater shock wave in the infinite water and near air-water surface and the physical characteristics of the air-water surface,three-dimensional numerical simulationof infinite water and near air-water surface underwater explosion was carried out based on the arbitrary Lagrangian-Eulerianmethod by finite eldment software ANSYS/LS-DYNA.The interaction between the water and the air during the process of explosion is investigated .According to analysis,we found that in the condition of the depth of detonation remaining unchanged, the influence of air-water surface on shock wave is mainly reflected in reducing the pulse width of incident shock wave and reducing the peak pressure of shock wave with the decrease of sounding depth. The height of water column produced by the same TNT explosive on the air-water surface increases with the decrease of the detonation depth. At the same time, the density distribution near air-water surfaceand the process of water column forming under different detonation depths are qualitatively analyzed, which is also reproduced with three-dimensional numerical simulation method.With the numerical simulation method, the characteristics of the shock wave values are analyzed and certify that the model has better calculation accuracy compared with the empirical formula,and the process of underwater explosion near air-water surface is also represented.
In order to study the pressure characteristics of the underwater shock wave in the infinite water and near air-water surface and the physical characteristics of the air-water surface,three-dimensional numerical simulationof infinite water and near air-water surface underwater explosion was carried out based on the arbitrary Lagrangian-Eulerianmethod by finite eldment software ANSYS/LS-DYNA.The interaction between the water and the air during the process of explosion is investigated .According to analysis,we found that in the condition of the depth of detonation remaining unchanged, the influence of air-water surface on shock wave is mainly reflected in reducing the pulse width of incident shock wave and reducing the peak pressure of shock wave with the decrease of sounding depth. The height of water column produced by the same TNT explosive on the air-water surface increases with the decrease of the detonation depth. At the same time, the density distribution near air-water surfaceand the process of water column forming under different detonation depths are qualitatively analyzed, which is also reproduced with three-dimensional numerical simulation method.With the numerical simulation method, the characteristics of the shock wave values are analyzed and certify that the model has better calculation accuracy compared with the empirical formula,and the process of underwater explosion near air-water surface is also represented.
2026,23(2):142-151
,DOI: 10.19951/j.cnki.1672-9331.20250312001
Abstract:
［Purposes ］ This study investigated the deterioration mechanisms of concrete ’s mechanical properties and microstructures under coupled sulfate and chromate erosion.The research establishes theoretical foundations for durability design and protection of concrete structures in harsh service environments.［Methods］ In practical engineering environments，coupled erosion solutions were prepared with varying sulfate ion，trivalent chromium，and hexavalent chromium concentrations.Wet -dry cycles were applied to simulate erosion processes.The corrosion resistance coefficient of compressive strength and the chloride ion migration coefficient of concrete were investigated.Microstructural morphology was observed using a scanning electron microscope （SEM）.Corrosion products were analyzed through X -ray diffraction （XRD）.［Results］ Compared to the standard curing condition，the compressive strength of concrete decreases by 4.2%-15.1% and the chloride ion migration coefficient increases by 69.2%-384.6% after 90 dry and wet cycles under coupled sulfate and chromium erosion.The analysis shows that the magnitude of change in compressive strength of concrete and chloride ion migration coefficient due to sulfate erosion is greater，while the magnitude of change in compressive strength of concrete and chloride ion migration coefficient due to chromium erosion is less.During the initial sulfate erosion phase，ettringite and gypsum are formed to fill concrete pores.In the later sulfate erosion phase，Ca（OH）2 is consumed and calcium silicate hydrate gel is degraded while ettringite is decomposed into gypsum.Sulfate and chromate penetration depths and content of corrosion products exhibit significant growth with increasing dry -wet cycles.［Conclusions ］ In the coupled sulfate and chromate erosion environment，it is mainly sulfate that dominates concrete deterioration through the calcite and gypsum expansion reaction，while chromium does not affect the morphology of the reaction products of sulfates，and their impact on performance can be disregarded.Moreover，no significant mutual promotion or inhibition is found when the two coexist.Dry-wet cycles accelerate ion migration and pore structure destruction，thus further weakening the durability of concrete.Therefore，for concrete projects in coupled sulfate and chromate erosion environments，the prevention and control measures of sulfate erosion in dry and wet alternating zones should be implemented to prolong the service life of concrete.
［Purposes ］ This study investigated the deterioration mechanisms of concrete ’s mechanical properties and microstructures under coupled sulfate and chromate erosion.The research establishes theoretical foundations for durability design and protection of concrete structures in harsh service environments.［Methods］ In practical engineering environments，coupled erosion solutions were prepared with varying sulfate ion，trivalent chromium，and hexavalent chromium concentrations.Wet -dry cycles were applied to simulate erosion processes.The corrosion resistance coefficient of compressive strength and the chloride ion migration coefficient of concrete were investigated.Microstructural morphology was observed using a scanning electron microscope （SEM）.Corrosion products were analyzed through X -ray diffraction （XRD）.［Results］ Compared to the standard curing condition，the compressive strength of concrete decreases by 4.2%-15.1% and the chloride ion migration coefficient increases by 69.2%-384.6% after 90 dry and wet cycles under coupled sulfate and chromium erosion.The analysis shows that the magnitude of change in compressive strength of concrete and chloride ion migration coefficient due to sulfate erosion is greater，while the magnitude of change in compressive strength of concrete and chloride ion migration coefficient due to chromium erosion is less.During the initial sulfate erosion phase，ettringite and gypsum are formed to fill concrete pores.In the later sulfate erosion phase，Ca（OH）2 is consumed and calcium silicate hydrate gel is degraded while ettringite is decomposed into gypsum.Sulfate and chromate penetration depths and content of corrosion products exhibit significant growth with increasing dry -wet cycles.［Conclusions ］ In the coupled sulfate and chromate erosion environment，it is mainly sulfate that dominates concrete deterioration through the calcite and gypsum expansion reaction，while chromium does not affect the morphology of the reaction products of sulfates，and their impact on performance can be disregarded.Moreover，no significant mutual promotion or inhibition is found when the two coexist.Dry-wet cycles accelerate ion migration and pore structure destruction，thus further weakening the durability of concrete.Therefore，for concrete projects in coupled sulfate and chromate erosion environments，the prevention and control measures of sulfate erosion in dry and wet alternating zones should be implemented to prolong the service life of concrete.
2026,23(2):177-190
,DOI: 10.19951/j.cnki.1672-9331.20251017001
Abstract:
［Purposes ］ This paper aims to analyze the impact of green technical efficiency uncertainty on green supply chain decision -making under different supply chain power structures and to explore the mechanism of the game relationship between the manufacturer and the retailer on the green level and pricing strategy.［Methods］ Under the condition of technical efficiency uncertainty，game models between the manufacturer and the retailer were constructed under four supply chain power structures：manufacturer -leader -retailer （MLR），retailer -leader -manufacturer （RLM），manufacturer -onpar -retailer （MOR），and centralized （C） decision -making.The Stackelberg game and Nash game methods were respectively adopted to analyze the optimal decision solutions under each structure，and numerical simulations were conducted to compare the impacts of technical efficiency uncertainty on the green level and price under different structures.［Results］ An increase in the mean value of technical efficiency helps improve the green level，but pricing strategies vary under different power structures.The MOR power structure has more advantages in green investment and anti -risk capability.When volatility increases，the C power structure and MOR power structure exhibit stronger stability.［Conclusions ］ The uncertainty of green technical efficiency and the supply chain power structure jointly affect green supply chain decision -making.The research results can provide a reference for enterprises to select suitable cooperation structures and formulate green strategies and provide theoretical support for policymakers.
［Purposes ］ This paper aims to analyze the impact of green technical efficiency uncertainty on green supply chain decision -making under different supply chain power structures and to explore the mechanism of the game relationship between the manufacturer and the retailer on the green level and pricing strategy.［Methods］ Under the condition of technical efficiency uncertainty，game models between the manufacturer and the retailer were constructed under four supply chain power structures：manufacturer -leader -retailer （MLR），retailer -leader -manufacturer （RLM），manufacturer -onpar -retailer （MOR），and centralized （C） decision -making.The Stackelberg game and Nash game methods were respectively adopted to analyze the optimal decision solutions under each structure，and numerical simulations were conducted to compare the impacts of technical efficiency uncertainty on the green level and price under different structures.［Results］ An increase in the mean value of technical efficiency helps improve the green level，but pricing strategies vary under different power structures.The MOR power structure has more advantages in green investment and anti -risk capability.When volatility increases，the C power structure and MOR power structure exhibit stronger stability.［Conclusions ］ The uncertainty of green technical efficiency and the supply chain power structure jointly affect green supply chain decision -making.The research results can provide a reference for enterprises to select suitable cooperation structures and formulate green strategies and provide theoretical support for policymakers.
2022,19(1):1-11
,DOI: 10.19951/j.cnki.1672-9331.2022.01.001
Abstract:
[Purposes]The paper aims to explore the effectiveness of the multi-scale algo- rithm in studying the mechanical characteristics of splitting fatigue damage of asphalt mix-ture．[Methods]By dividing five scale areas, the multi-scale analysis of five different gradations of asphalt mixtures was conducted, the splitting strengths were calculated under different fatigue damage degrees,the splitting strengths obtained by the indoor test and the multi-scale algorithm were compared and analyzed to verify the rationality of the multi-scale algorithm in studying the mechanical characteristics of splitting fatigue damage of asphalt mixture. [Findings]The splitting strength of asphalt mixture with aggregate particle size of 1.18-2.36 mm has been greatly improved, the absolute values of relative errors between the splitting strengths obtained by the multi-scale algorithm and that obtained by the indoor test are all within 10%, which meets the engineering accuracy requirements. [Conclusions]The multi-scale algorithm is feasible to study the mechanical characteristics of splitting fatigue damage of asphalt mixture, and has certain application value in practical engineering.
[Purposes]The paper aims to explore the effectiveness of the multi-scale algo- rithm in studying the mechanical characteristics of splitting fatigue damage of asphalt mix-ture．[Methods]By dividing five scale areas, the multi-scale analysis of five different gradations of asphalt mixtures was conducted, the splitting strengths were calculated under different fatigue damage degrees,the splitting strengths obtained by the indoor test and the multi-scale algorithm were compared and analyzed to verify the rationality of the multi-scale algorithm in studying the mechanical characteristics of splitting fatigue damage of asphalt mixture. [Findings]The splitting strength of asphalt mixture with aggregate particle size of 1.18-2.36 mm has been greatly improved, the absolute values of relative errors between the splitting strengths obtained by the multi-scale algorithm and that obtained by the indoor test are all within 10%, which meets the engineering accuracy requirements. [Conclusions]The multi-scale algorithm is feasible to study the mechanical characteristics of splitting fatigue damage of asphalt mixture, and has certain application value in practical engineering.
2026,23(2):116-130
,DOI: 10.19951/j.cnki.1672-9331.20251128001
Abstract:
［Purposes ］ This paper aims to address the optimization problem of cementitious component proportions for flowable fill materials using recycled powder from asphalt mixing plants.［Methods］ This paper analyzed the influence of cement，fly ash，and slag powder contents on the workability （fluidity and bleeding rate ） and mechanical properties （7 d and 28 d compressive strengths） based on the response surface methodology （Box-Behnken design ）.Furthermore，the hydration mechanism was revealed through micro -tests including X -ray diffraction （XRD），infrared spectroscopy （IR），and scanning electron microscopy （SEM）.［Results］ The results indicate that fluidity is primarily dominated by the fly ash content，followed by cement and slag powder，and the cement -fly ash interaction significantly improves flowability at low and medium contents.The bleeding rate exhibits a nonlinear relationship with the cement content，reaching the minimum at a cement content of 6% and a fly ash content of 5%.Slag powder makes the greatest contribution to compressive strength，and its interactions with fly ash and cement are significant.Under the optimized proportion of cementitious components （the ratio of cement to fly ash to slag powder is 33∶26∶41），the model prediction error is less than 5%.The optimal proportion is determined as a ratio of recycled powder，cement，fly ash，and slag powder of 100∶7.28∶5.78∶8.99，with a water -solid ratio of 0.39 and a water -reducing agent of 1.7%.The comprehensive performance indicators are as follows：fluidity is 209 mm；bleeding rate is 3.93%；7 d compressive strength is 3.34 MPa，and 28 d compressive strength is 7.88 MPa.The hydration products of the flowable fill materials using recycled powder are mainly C -S-H gels，and the pozzolanic effect of fly ash and slag powder promotes the formation of C -S-H gels.［Conclusions ］ This proportion combines environmental protection and engineering applicability，providing experimental technical support for the design of flowable fill materials using recycled powder.
［Purposes ］ This paper aims to address the optimization problem of cementitious component proportions for flowable fill materials using recycled powder from asphalt mixing plants.［Methods］ This paper analyzed the influence of cement，fly ash，and slag powder contents on the workability （fluidity and bleeding rate ） and mechanical properties （7 d and 28 d compressive strengths） based on the response surface methodology （Box-Behnken design ）.Furthermore，the hydration mechanism was revealed through micro -tests including X -ray diffraction （XRD），infrared spectroscopy （IR），and scanning electron microscopy （SEM）.［Results］ The results indicate that fluidity is primarily dominated by the fly ash content，followed by cement and slag powder，and the cement -fly ash interaction significantly improves flowability at low and medium contents.The bleeding rate exhibits a nonlinear relationship with the cement content，reaching the minimum at a cement content of 6% and a fly ash content of 5%.Slag powder makes the greatest contribution to compressive strength，and its interactions with fly ash and cement are significant.Under the optimized proportion of cementitious components （the ratio of cement to fly ash to slag powder is 33∶26∶41），the model prediction error is less than 5%.The optimal proportion is determined as a ratio of recycled powder，cement，fly ash，and slag powder of 100∶7.28∶5.78∶8.99，with a water -solid ratio of 0.39 and a water -reducing agent of 1.7%.The comprehensive performance indicators are as follows：fluidity is 209 mm；bleeding rate is 3.93%；7 d compressive strength is 3.34 MPa，and 28 d compressive strength is 7.88 MPa.The hydration products of the flowable fill materials using recycled powder are mainly C -S-H gels，and the pozzolanic effect of fly ash and slag powder promotes the formation of C -S-H gels.［Conclusions ］ This proportion combines environmental protection and engineering applicability，providing experimental technical support for the design of flowable fill materials using recycled powder.
2026,23(2):131-141
,DOI: 10.19951/j.cnki.1672-9331.20260123001
Abstract:
［Purposes ］ Given the widespread water damage in early pavement distress and its significant restriction on pavement lifespan and service performance，this paper aims to provide a basis for optimizing the design and application of recycled mixtures by analyzing the effect of the blending degree of new and aged asphalt on the water stability of recycled hot -mix asphalt mixture （RHAM）.［Methods］ First，the blending degree of new and aged asphalt during the hot -mixing process was quantitatively analyzed using a Fourier transform infrared spectrometer （FTIR）.Then，the FTIR results were validated using a dynamic shear rheometer （DSR）.Finally，the porosity，indirect tensile strength （ITS），and tensile strength ratio （TSR） of the mixtures with different blending degrees were evaluated through freeze -thaw cycle tests.On this basis，the relationship between the blending degree of new and aged asphalt and the water stability of RHAM was established.［Results］ Extending the mixing duration and reducing the content of reclaimed asphalt pavement （RAP） can effectively improve the blending degree of new and aged asphalt，thereby enhancing the water stability of the mixture.When the blending degree is greater than 81.6%，the increment in porosity of RHAM decreases with the increase in the number of freeze -thaw cycles.However，under the condition of a low blending degree，the freeze -thaw action leads to a significant increase in porosity and a significant decrease in TSR and water stability.［Conclusions ］ The blending degree of new and aged asphalt is a key factor affecting the water stability of RHAM.A higher blending degree can significantly improve the resistance of the mixture to water damage.This paper provides a theoretical basis for the mix design and process control of recycled asphalt mixture，which helps to extend the pavement service life and improve its service performance.
［Purposes ］ Given the widespread water damage in early pavement distress and its significant restriction on pavement lifespan and service performance，this paper aims to provide a basis for optimizing the design and application of recycled mixtures by analyzing the effect of the blending degree of new and aged asphalt on the water stability of recycled hot -mix asphalt mixture （RHAM）.［Methods］ First，the blending degree of new and aged asphalt during the hot -mixing process was quantitatively analyzed using a Fourier transform infrared spectrometer （FTIR）.Then，the FTIR results were validated using a dynamic shear rheometer （DSR）.Finally，the porosity，indirect tensile strength （ITS），and tensile strength ratio （TSR） of the mixtures with different blending degrees were evaluated through freeze -thaw cycle tests.On this basis，the relationship between the blending degree of new and aged asphalt and the water stability of RHAM was established.［Results］ Extending the mixing duration and reducing the content of reclaimed asphalt pavement （RAP） can effectively improve the blending degree of new and aged asphalt，thereby enhancing the water stability of the mixture.When the blending degree is greater than 81.6%，the increment in porosity of RHAM decreases with the increase in the number of freeze -thaw cycles.However，under the condition of a low blending degree，the freeze -thaw action leads to a significant increase in porosity and a significant decrease in TSR and water stability.［Conclusions ］ The blending degree of new and aged asphalt is a key factor affecting the water stability of RHAM.A higher blending degree can significantly improve the resistance of the mixture to water damage.This paper provides a theoretical basis for the mix design and process control of recycled asphalt mixture，which helps to extend the pavement service life and improve its service performance.
2023,20(6):109-118
,DOI: 10.19951/j.cnki.1672-9331.20230524001
Abstract:
[Purposes] In order to meet the customized requirements of low energy-consumption and light-weight elevator car, a variation design framework of modular car structure based on "Internet + " is constructed. [Methods] First of all, under the B/S architecture, Vue technology was used to develop user-defined design data acquisition front-end to obtain customized design requirements, and Springboot technology was used to develop modular structure variation design back-end. A Web framework for front-end separation was built, which can realize bidirectional binding of front-end and back-end data. Secondly, a topology optimization design method for high-specific stiffness considering stress constraints was embedded in the back end. The strength and volume fraction of the car structure was considered as user-defined constraints，and the maximum stiffness of the car modular structure was optimized as the optimization goal. The moving asymptotic optimization algorithm was used as the solver to drive the rapid customized variation design of the lightweight car modular structure. Then, the heavyside function was introduced into the optimization method to ensure that the design results have clear geometric boundaries. Finally, taking a certain type of backpack elevator car frame as an example, the geometric and mechanical boundary parameters of the car structure were set in the user-defined interface to carry out the variation design of the innovative lightweight car frame structure, and the finite element simulation analysis was carried out. [Findings] Under the premise of given design requirements, the structural variation process was stable and convergent, and the geometric boundary of the designed structure was clear. Under the same mechanical boundary conditions and meeting the 2 times minimum safety factor of the material, the mass of the designed car frame structure reduced 16.09% comparing with the original structure.The structural deformation was ensured to meet the practical application requirements, and the specific stiffness was significantly improved, which verified the effectiveness of the structural variation design framework established in this paper. [Conclusions] The proposed design framework can improve the specific stiffness of the structure under the premise of ensuring the strength of the structure, which can be effectively applied to the rapid customized design of the lightweight elevator car modular structure. It can shorten the design cycle of the car modular structure, and enrich the design means of the car modular structure.
[Purposes] In order to meet the customized requirements of low energy-consumption and light-weight elevator car, a variation design framework of modular car structure based on "Internet + " is constructed. [Methods] First of all, under the B/S architecture, Vue technology was used to develop user-defined design data acquisition front-end to obtain customized design requirements, and Springboot technology was used to develop modular structure variation design back-end. A Web framework for front-end separation was built, which can realize bidirectional binding of front-end and back-end data. Secondly, a topology optimization design method for high-specific stiffness considering stress constraints was embedded in the back end. The strength and volume fraction of the car structure was considered as user-defined constraints，and the maximum stiffness of the car modular structure was optimized as the optimization goal. The moving asymptotic optimization algorithm was used as the solver to drive the rapid customized variation design of the lightweight car modular structure. Then, the heavyside function was introduced into the optimization method to ensure that the design results have clear geometric boundaries. Finally, taking a certain type of backpack elevator car frame as an example, the geometric and mechanical boundary parameters of the car structure were set in the user-defined interface to carry out the variation design of the innovative lightweight car frame structure, and the finite element simulation analysis was carried out. [Findings] Under the premise of given design requirements, the structural variation process was stable and convergent, and the geometric boundary of the designed structure was clear. Under the same mechanical boundary conditions and meeting the 2 times minimum safety factor of the material, the mass of the designed car frame structure reduced 16.09% comparing with the original structure.The structural deformation was ensured to meet the practical application requirements, and the specific stiffness was significantly improved, which verified the effectiveness of the structural variation design framework established in this paper. [Conclusions] The proposed design framework can improve the specific stiffness of the structure under the premise of ensuring the strength of the structure, which can be effectively applied to the rapid customized design of the lightweight elevator car modular structure. It can shorten the design cycle of the car modular structure, and enrich the design means of the car modular structure.
2023,20(5):1-24
,DOI: 10.19951/j.cnki.1672-9331.20231008002
Abstract:
Geopolymer is a new type of inorganic cementitious material developed in recent years. It not only realizes the resource reuse of industrial solid wastes, but also contributes to the reduced energy consumption and greenhouse gas emissions, and is considered a green cementitious material with the potential to replace ordinary Portland cement (OPC). To address the durability of geopolymer concrete, this paper compared and summarized the durability performance of geopolymer concrete and cement-based concrete from four aspects, namely, the resistance to chemical attack (salt and acid resistance), carbonation, chloride penetration, and frost resistance. It was found that geopolymer concrete exhibited superior chemical resistance, chloride penetration resistance, and frost resistance, but slightly lower carbonation resistance than cement-based concrete. However, due to the diversity of raw materials, the microstructure, mechanical properties, and deterioration mechanisms were different for each type of geopolymer concrete, thereby resulting in large differences in their durability. Under these environmental attacks, the deterioration mechanisms of geopolymer concrete were mainly attributed to the dissolved hydration products, the formed expansion products, the generated cracks, and the increased porosity.
Geopolymer is a new type of inorganic cementitious material developed in recent years. It not only realizes the resource reuse of industrial solid wastes, but also contributes to the reduced energy consumption and greenhouse gas emissions, and is considered a green cementitious material with the potential to replace ordinary Portland cement (OPC). To address the durability of geopolymer concrete, this paper compared and summarized the durability performance of geopolymer concrete and cement-based concrete from four aspects, namely, the resistance to chemical attack (salt and acid resistance), carbonation, chloride penetration, and frost resistance. It was found that geopolymer concrete exhibited superior chemical resistance, chloride penetration resistance, and frost resistance, but slightly lower carbonation resistance than cement-based concrete. However, due to the diversity of raw materials, the microstructure, mechanical properties, and deterioration mechanisms were different for each type of geopolymer concrete, thereby resulting in large differences in their durability. Under these environmental attacks, the deterioration mechanisms of geopolymer concrete were mainly attributed to the dissolved hydration products, the formed expansion products, the generated cracks, and the increased porosity.
2022,19(3):104-121
,DOI: 10.19951/j.cnki.1672-9331.2022.03.011
Abstract:
Traveling wave location technology can quickly and accurately locate the fault according to the collected time information when the high-voltage AC transmission line fault occurs in the system. Due to its high location accuracy, it has attracted extensive attention. This paper introduces the development of traveling wave location technology at home and abroad from the aspects of accurate detection of traveling wave signal, high-precision synchronous clock technology, fault location algorithm and engineering practice. Then it introduces the working principles and their advantages and disadvantages of single-end traveling wave location, double-end traveling wave location and network traveling wave location methods. The main technical problems existing in the traditional traveling wave location research have been analysed, which puts forward the corresponding solutions. Finally, the development prospect of traveling wave location technology is prospected, in order to provide reference for subsequent research.
Traveling wave location technology can quickly and accurately locate the fault according to the collected time information when the high-voltage AC transmission line fault occurs in the system. Due to its high location accuracy, it has attracted extensive attention. This paper introduces the development of traveling wave location technology at home and abroad from the aspects of accurate detection of traveling wave signal, high-precision synchronous clock technology, fault location algorithm and engineering practice. Then it introduces the working principles and their advantages and disadvantages of single-end traveling wave location, double-end traveling wave location and network traveling wave location methods. The main technical problems existing in the traditional traveling wave location research have been analysed, which puts forward the corresponding solutions. Finally, the development prospect of traveling wave location technology is prospected, in order to provide reference for subsequent research.
2023,20(6):91-99
,DOI: 10.19951/j.cnki.1672-9331.20220417001
Abstract:
[Purposes] This work aims to demonstrate the semi-open graded asphalt mixture BK-7 with a nominal maximum particle size of 7 mm. [Methods] In this paper, the mineral composition formulation of BK-7 mixture was designed. The amount of SBS modified asphalt was determined by Schellenberg leakage test and Kantabaugh flying test when the fiber content was 0.4%. Uniaxial penetration test, low temperature bending test and Marshall stability test of BK-7 mixture with 9%, 11% and 13% porosity were carried out, and the corresponding properties of BK-7 mixture were compared with those of SMA-5, AC-5 and OGFC-5. At the same time, flying and Marshall tests were carried out on BK-7 mixture with 11% porosity soaked in acid solution. [Findings] Among the three kinds of BK-7 mixture, the BK-7 mixture with 9% porosity has the best road performance and the best rutting resistance, and its low temperature crack resistance and water stability are comparable to those of SMA-5 and AC-5 asphalt mixture. After soaking in acid rain solution with pH=4 for 2 cycles (" Soaking for 7 days, natural drying for 1 day "for 1 cycle), the Marshall stability of BK-7 mixture with 11% porosity and the flight loss of Fort Kenta could meet the corresponding specification requirements. [Conclusions] The road performance of BK-7 asphalt mixture with 9% porosity of SBS modified asphalt mixed with fiber has comparative advantages, and it has certain engineering application value in South China where exhibits a high-temperature climate throughout a year.
[Purposes] This work aims to demonstrate the semi-open graded asphalt mixture BK-7 with a nominal maximum particle size of 7 mm. [Methods] In this paper, the mineral composition formulation of BK-7 mixture was designed. The amount of SBS modified asphalt was determined by Schellenberg leakage test and Kantabaugh flying test when the fiber content was 0.4%. Uniaxial penetration test, low temperature bending test and Marshall stability test of BK-7 mixture with 9%, 11% and 13% porosity were carried out, and the corresponding properties of BK-7 mixture were compared with those of SMA-5, AC-5 and OGFC-5. At the same time, flying and Marshall tests were carried out on BK-7 mixture with 11% porosity soaked in acid solution. [Findings] Among the three kinds of BK-7 mixture, the BK-7 mixture with 9% porosity has the best road performance and the best rutting resistance, and its low temperature crack resistance and water stability are comparable to those of SMA-5 and AC-5 asphalt mixture. After soaking in acid rain solution with pH=4 for 2 cycles (" Soaking for 7 days, natural drying for 1 day "for 1 cycle), the Marshall stability of BK-7 mixture with 11% porosity and the flight loss of Fort Kenta could meet the corresponding specification requirements. [Conclusions] The road performance of BK-7 asphalt mixture with 9% porosity of SBS modified asphalt mixed with fiber has comparative advantages, and it has certain engineering application value in South China where exhibits a high-temperature climate throughout a year.
2022,19(1):73-80
,DOI: 10.19951/j.cnki.1672-9331.2022.01.009
Abstract:
[Purposes]The paper explores the use of "bigdata"to innovate the prediction method of urban residents'travel volume(OD), improve the time-consuming,laborious and inaccurate problems of traditional urban residents'travel survey methods, and also provide reliable data support for urban public transportation planning and management. [Methods] Combining the characteristics and advantages of mobile phone signaling data,bus IC card, bus GPS and subway gate data, the OD matrix of urban residents'public transportation travel was obtained by cluster analysis and other methods,and the wavelet neural network combined with optimized whale algorithm (IWOA-WNN)was used to predict the travel OD matrix of future time period. Taking Changsha City as an example, the original data during the 60 d evening peak period were selected, the IWOA-WNN was used for prediction, and the time series method was combined for analysis. [Findings]Compared with the wavelet neural network before optimization, the prediction results of IWOA-WNN are closer to the actual situation, and the accuracy reaches 93.36%. [Conclusions]The methods of data processing and prediction proposed in this study have higher accuracy.
[Purposes]The paper explores the use of "bigdata"to innovate the prediction method of urban residents'travel volume(OD), improve the time-consuming,laborious and inaccurate problems of traditional urban residents'travel survey methods, and also provide reliable data support for urban public transportation planning and management. [Methods] Combining the characteristics and advantages of mobile phone signaling data,bus IC card, bus GPS and subway gate data, the OD matrix of urban residents'public transportation travel was obtained by cluster analysis and other methods,and the wavelet neural network combined with optimized whale algorithm (IWOA-WNN)was used to predict the travel OD matrix of future time period. Taking Changsha City as an example, the original data during the 60 d evening peak period were selected, the IWOA-WNN was used for prediction, and the time series method was combined for analysis. [Findings]Compared with the wavelet neural network before optimization, the prediction results of IWOA-WNN are closer to the actual situation, and the accuracy reaches 93.36%. [Conclusions]The methods of data processing and prediction proposed in this study have higher accuracy.
2023,20(3):14-31
,DOI: 10.19951/j.cnki.1672-9331.20220913001
Abstract:
Recent years, with the massive consumption of lithium and the strong increase in the price of lithium, the application of lithium battery is limited in some extent.?With the similar working principle and battery components, sodium-ion batteries have exhibited a great opportunity for development and attracted extensive attention of many researchers.?Polyanionic compounds have the advantages of high and stable voltage platform, diverse structure, stable structure and fast diffusion rate of sodium-ions, which have become the research hotspot of cathode materials for sodium batteries. However, their large anionic groups lead to poor electron rate, which limits the specific capacity and rate capability of the materials.?In this review, the research status of various polyanionic cathode materials is mentioned, which have discussed the relationship between crystal structure and electrochemical properties of the materials, some modification strategies including element doping and substitution, carbon coating and carbon recombination, and nanostructure design.
Recent years, with the massive consumption of lithium and the strong increase in the price of lithium, the application of lithium battery is limited in some extent.?With the similar working principle and battery components, sodium-ion batteries have exhibited a great opportunity for development and attracted extensive attention of many researchers.?Polyanionic compounds have the advantages of high and stable voltage platform, diverse structure, stable structure and fast diffusion rate of sodium-ions, which have become the research hotspot of cathode materials for sodium batteries. However, their large anionic groups lead to poor electron rate, which limits the specific capacity and rate capability of the materials.?In this review, the research status of various polyanionic cathode materials is mentioned, which have discussed the relationship between crystal structure and electrochemical properties of the materials, some modification strategies including element doping and substitution, carbon coating and carbon recombination, and nanostructure design.
Copyright Information
- ParentUnit：Hunan Provincial Department of Education
- Organizers：Changsha University of Science & Technology
- Editor in chief：ZHENG Jianlong
- Executive Editor：ZHAO Bing
- PublishHouse：Editorial Office of Journal of Changsha University of Science & Technology (Natural Science)
- Printing：Hunan High-speed Printing Co., Ltd.
- Domestic release：湖南省邮政报刊发行局
- CN：43-1444/N
- ISSN：1672-9331
- PostID：42-304
- Address：No. 960, Section 2, Wanjiali South Road, Tianxin District, Changsha, Hunan Province 410114, P.R. China
- Postcode：410114
- Telephone：0731-85258192
- E-mail：lgdxxb2010@126.com
External Links Links
Official Account
Journal of Changsha University of Science & Technology (Natural Science) ® 2026 All Rights Reserved