压-剪耦合冲击下冻土力学行为与能量演化研究  

Study on Mechanical Behavior and Energy Evolution of Frozen Soil Under Compression-Shear Impact Loading

作　　者：王艳薇 朱志武[1] WANG Yanwei;ZHU Zhiwu(School of Mechanics and Aerospace Engineering,Southwest Jiaotong University,Chengdu 611756,China)

机构地区：[1]西南交通大学力学与航空航天学院,成都611756

出　　处：《四川轻化工大学学报（自然科学版）》2023年第6期73-80,共8页Journal of Sichuan University of Science & Engineering(Natural Science Edition)

基　　金：四川省自然科学基金项目(2022NSFSC0420)。

摘　　要：在寒区工程施工中,冻土不可避免地会承受压-剪耦合荷载的作用。为了研究冻土在压-剪耦合冲击加载下的力学性能及其能量演化规律,设计了4种不同倾角(0°、3°、5°和7°)的冻土试样,并利用分离式霍普金森压杆在3组不同冻结温度(-23、-15、-7℃)下对其进行冲击实验。结果表明:压-剪耦合冲击加载下冻土的破坏过程可以分为弹性阶段、塑性阶段和破坏阶段;随着温度由-23℃升至-7℃,0°倾角下冻土的抗压强度下降了41.4%,表现出明显的温度敏感性,而当倾角由0°增加至7°时,-23℃下冻土的抗压强度降低了21.0%,表现出一定的加载路径依赖性;冻土的破坏面随着温度降低不断向外扩展;冻土的破坏过程伴随着能量积累、耗散和释放,且能量耗散密度随着温度的升高和倾角的增加而降低。Frozen soil is inevitably subjected to compression-shear dynamic loading in the construction of cold region engineering.To study the mechanical properties and energy evolution of frozen soil under compression-shear impact loading,four kinds of frozen soil samples with different tilt angles(0°,3°,5°,7°)are designed,and the impact experiments are carried out with split Hopkinson pressure bar at three different freezing temperatures(-23℃,-15℃,-7℃).The results show that the failure process of frozen soil under compression�shear impact loading can be divided into elastic stage,plastic stage and failure stage.The compressive strength of 0°samples decreased by 41.4%with the temperature increasing from-23℃to-7℃,while the compressive strength at-23℃decreased by 21.0%with the tilt angle increasing from 0°to 7°.The compressive strength of frozen soil shows obvious temperature-sensitive and certain load-path dependent.The failure surface of frozen soil continuously expands outward with the decrease of temperature.The damage process of frozen soil is accompanied by energy accumulation,dissipation and release,and the energy dissipation density decreases with the increase of tilt angle and temperature.

关 键 词：冻土 冲击 压-剪耦合 能量演化 破坏面 

分 类 号：O347.3[理学—固体力学]