冻融循环下黄河堤岸砂质壤土宏细观破坏过程  

Macroscopic and microscopic damage processes of sandy loam soils in Yellow River embankment under freeze-thaw cycles

作　　者：张江浩 冀鸿兰[1,2] 杨震 李志军 刘晓民[1,2] ZHANG Jianghao;JI Honglan;YANG Zhen;LI Zhijun;LIU Xiaomin(College of Water Conservancy and Civil Engineering,Inner Mongolia Agricultural University,Hohhot 010018,China;Autonomous Region Collaborative Innovation Center for Integrated Water Resources and Water Environment in Inner Mongolia Section of Yellow River Basin,Hohhot 010018,China;State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]内蒙古农业大学水利与土木建筑工程学院,内蒙古呼和浩特010018 [2]黄河流域内蒙段水资源与水环境综合治理自治区协同创新中心,内蒙古呼和浩特010018 [3]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024

出　　处：《河海大学学报（自然科学版）》2024年第6期69-80,共12页Journal of Hohai University(Natural Sciences)

基　　金：国家自然科学基金联合基金项目(U23A2012);国家自然科学基金项目(52379014);内蒙古自然科学基金重点项目(2022ZD08);内蒙古自然科学基金青年基金项目(2023QN05026);内蒙古博士研究生科研创新项目(B20231084Z)。

摘　　要：为揭示黄河堤岸砂质壤土在冻融循环下的宏细观破坏规律,通过三轴剪切试验和离散元数值模拟分析了堤岸砂质壤土在不同冻融循环次数下的抗剪强度变化、形变破坏特征、力链发展趋势和组构张量演化规律。结果表明:冻融循环会显著降低砂质壤土的抗剪强度,诱发砂质壤土产生冻胀融沉,抗剪强度平均损失率在15次冻融循环后达到了24.06%;冻融循环后砂质壤土鼓胀破坏区最大直径变小,接触力最大值平均降幅为26.89%;冻融循环后法向接触数目组构张量略微增大,法向接触力组构张量明显降低,各向异性程度减弱;冻融循环前后砂质壤土强接触和全接触等效各向异性均低于冻融前,强接触等效各向异性系数与偏应力变化趋势基本一致。基于离散元模拟结果建立了一种以冻融循环次数为控制参数的堤岸砂质壤土抗剪强度预测模型,具有较好的预测效果。In order to reveal the macroscopic and microscopic damage law of sandy loam on the embankment of the Yellow River under freeze-thaw cycles,the changes in the shear strength,the deformation damage characteristics,the development trend of force chain,and the evolution of fabric tensor of sandy loam on the embankment were analyzed by the triaxial shear test and the numerical simulation of the discrete element under different numbers of freeze-thaw cycles.The results showed that freeze-thaw cycles significantly reduced the shear strength of sandy loam and induced the sandy loam to freeze and thaw,with the average loss of shear strength by 24.06%after 15 freeze-thaw cycles.The maximum diameter of the bulging damage zone of sandy loam became smaller after freeze-thaw cycles,and the average decrease of maximum contact force was 26.89%.The normal contact number of fabric tensor increased slightly after the freeze-thaw cycle,the normal contact force group tensor decreased significantly,and the degree of anisotropy was weakened.The strong-contact and full-contact equivalent anisotropies of sandy loam before and after the freeze-thaw cycle were lower than that before the freeze-thaw cycle,and the strong-contact equivalent anisotropy coefficients showed the same as the trend of bias stress change.Based on the discrete element simulation results,a prediction model for the shear strength of embankment sandy loam with the number of freeze-thaw cycles as the control parameter was established,with a better prediction effect.

关 键 词：砂质壤土 黄河堤岸 冻融循环 离散元数值模拟 组构张量 各向异性 

分 类 号：TU432[建筑科学—岩土工程] TV84[建筑科学—土工工程]