The latticed dunes in the Tengger Desert are widely distributed,and the sand-blocking fence placed here are highly susceptible to local failure due to complex wind-sand activities,posing a serious threat to the safe o...The latticed dunes in the Tengger Desert are widely distributed,and the sand-blocking fence placed here are highly susceptible to local failure due to complex wind-sand activities,posing a serious threat to the safe operation of the highway.To explore the local failure mechanism of sand-blocking fence in the latticed dune area,the local failure of sand-blocking fence in the latticed dune areas along the Wuhai-Maqin Highway in China was observed.Taking the first main ridge of the latticed dune as the placement location,the structure of the wind-sand flow field of sand-blocking fence placed at top,the bottom and the middle of windward slope was analyzed by Computational Fluid Dynamics(CFD).The results show that when placed at top of the first main ridge,the wind speed near the sand-blocking fence is the highest,up to 15.23 m/s.Therefore,the wind load strength on the sand barrier is correspondingly larger,up to 232.61 N∙m-2.As the strength of material continues to decrease,the nylon net is prone to breakage.The roots of the angle steel posts are susceptible to hollowing by vortex action,which can cause sand-blocking fence to fall over in strong wind conditions.When placed at the bottom of windward slope,wind speed drop near sand-blocking fence is greatest,with the decrease of 12.48-14.32 m/s compared to the original wind speed.This is highly likely to lead to large-scale deposition of sand particles and burial of the sand-blocking fence.When placed in the middle of windward slope,sand-blocking fence is subjected to less wind load strength(168.61N∙m-2)and sand particles are mostly deposited at the bottom of windward slope,with only a small amount of sand accumulating at the root of sand-blocking fence.Based on field observations and numerical modelling results,when the sand-blocking fence is placed in latticed dune area,it should be placed in the middle of the windward slope of the first main ridge as a matter of priority.Besides the sand-blocking fence should be placed at the top of the first main ridge,and sand fixing measures should be added.展开更多
Sand control engineering plays a pivotal role in ensuring the safe operation of transportation corridors that traverse desertified areas.Evaluating the effectiveness of these interventions provides a crucial scientifi...Sand control engineering plays a pivotal role in ensuring the safe operation of transportation corridors that traverse desertified areas.Evaluating the effectiveness of these interventions provides a crucial scientific basis for mitigating aeolian hazards and guiding the sustainable management of fragile and arid ecosystems.In this study,we investigated a representative section of Highway S315,which is prone to windblown sand hazards,in Ejin Banner,northern China.By integrating segmented measurements with unmanned aerial vehicle(UAV)-based oblique photogrammetry,we quantitatively characterized the spatial and temporal evolution of sand accumulation around multiple sand control structures and assessed their blocking efficiency.Complementary road sand-removal records and meteorological observations were analyzed to evaluate the long-term performance of engineering measures.Our results showed that sand accumulation behind high vertical sand barriers typically exhibited a triangular cross-sectional morphology,with a gently inclined stoss slope and a steep lee slope.The shape and volume of these deposits evolved dynamically in response to variations in the prevailing wind regime,reflecting strong feedback between barrier geometry and local airflow redistribution.In contrast,the low-profile checkerboard sand barriers displayed a three-stage morphological trajectory—initial accumulation,edge intensification,and functional decline—indicating a progressive loss of sand-trapping capacity as burial proceeded.Sand accumulation was markedly greater on the highway's western(upwind)side than on the eastern(downwind)side,with 70.0%–90.0%of the airborne sediment flux intercepted by the upwind structures.From 2015 to 2020,mean annual wind speeds remained stable(2.68±0.04 m/s),while precipitation varied from 22.6 to 103.7 mm.However,the annual sand removal volume from the road decreased consistently,confirming the enhanced mitigation effect of multi-level protective system.These findings highlight the coupled interactions between engineering design,wind–sand dynamics,and topographic context.Beyond their immediate protective role,well-designed sand control systems also contribute to the prevention of regional desertification by stabilizing mobile dunes and fostering conditions favorable for ecological restoration.The insights gained here provide both theoretical and practical support for optimizing sand control engineering and advancing sustainable hazard mitigation in arid and semi-arid areas.展开更多
文摘The latticed dunes in the Tengger Desert are widely distributed,and the sand-blocking fence placed here are highly susceptible to local failure due to complex wind-sand activities,posing a serious threat to the safe operation of the highway.To explore the local failure mechanism of sand-blocking fence in the latticed dune area,the local failure of sand-blocking fence in the latticed dune areas along the Wuhai-Maqin Highway in China was observed.Taking the first main ridge of the latticed dune as the placement location,the structure of the wind-sand flow field of sand-blocking fence placed at top,the bottom and the middle of windward slope was analyzed by Computational Fluid Dynamics(CFD).The results show that when placed at top of the first main ridge,the wind speed near the sand-blocking fence is the highest,up to 15.23 m/s.Therefore,the wind load strength on the sand barrier is correspondingly larger,up to 232.61 N∙m-2.As the strength of material continues to decrease,the nylon net is prone to breakage.The roots of the angle steel posts are susceptible to hollowing by vortex action,which can cause sand-blocking fence to fall over in strong wind conditions.When placed at the bottom of windward slope,wind speed drop near sand-blocking fence is greatest,with the decrease of 12.48-14.32 m/s compared to the original wind speed.This is highly likely to lead to large-scale deposition of sand particles and burial of the sand-blocking fence.When placed in the middle of windward slope,sand-blocking fence is subjected to less wind load strength(168.61N∙m-2)and sand particles are mostly deposited at the bottom of windward slope,with only a small amount of sand accumulating at the root of sand-blocking fence.Based on field observations and numerical modelling results,when the sand-blocking fence is placed in latticed dune area,it should be placed in the middle of the windward slope of the first main ridge as a matter of priority.Besides the sand-blocking fence should be placed at the top of the first main ridge,and sand fixing measures should be added.
基金supported by the Gansu Provincial Science and Technology Planning Project(23ZDFA018)the Research Program of Construction Science and Technology Project of the Transportation Department of Inner Mongolia Autonomous Region,China(NJ-2018-29)the Gansu Province Longyuan Youth Talent Program,and the Doctoral Research Start-up Fund of Fuyang Normal University,China(2024KYQD0123).
文摘Sand control engineering plays a pivotal role in ensuring the safe operation of transportation corridors that traverse desertified areas.Evaluating the effectiveness of these interventions provides a crucial scientific basis for mitigating aeolian hazards and guiding the sustainable management of fragile and arid ecosystems.In this study,we investigated a representative section of Highway S315,which is prone to windblown sand hazards,in Ejin Banner,northern China.By integrating segmented measurements with unmanned aerial vehicle(UAV)-based oblique photogrammetry,we quantitatively characterized the spatial and temporal evolution of sand accumulation around multiple sand control structures and assessed their blocking efficiency.Complementary road sand-removal records and meteorological observations were analyzed to evaluate the long-term performance of engineering measures.Our results showed that sand accumulation behind high vertical sand barriers typically exhibited a triangular cross-sectional morphology,with a gently inclined stoss slope and a steep lee slope.The shape and volume of these deposits evolved dynamically in response to variations in the prevailing wind regime,reflecting strong feedback between barrier geometry and local airflow redistribution.In contrast,the low-profile checkerboard sand barriers displayed a three-stage morphological trajectory—initial accumulation,edge intensification,and functional decline—indicating a progressive loss of sand-trapping capacity as burial proceeded.Sand accumulation was markedly greater on the highway's western(upwind)side than on the eastern(downwind)side,with 70.0%–90.0%of the airborne sediment flux intercepted by the upwind structures.From 2015 to 2020,mean annual wind speeds remained stable(2.68±0.04 m/s),while precipitation varied from 22.6 to 103.7 mm.However,the annual sand removal volume from the road decreased consistently,confirming the enhanced mitigation effect of multi-level protective system.These findings highlight the coupled interactions between engineering design,wind–sand dynamics,and topographic context.Beyond their immediate protective role,well-designed sand control systems also contribute to the prevention of regional desertification by stabilizing mobile dunes and fostering conditions favorable for ecological restoration.The insights gained here provide both theoretical and practical support for optimizing sand control engineering and advancing sustainable hazard mitigation in arid and semi-arid areas.
