冻融循环下粗粒土路基动回弹模量衰变规律研究  

Study of decay law of dynamic resilience modulus of coarse-grained soil subgrade in freeze-thaw cycle

作　　者：冉武平[1,2] 陈慧敏 黄建军 李玲 艾贤臣[1,2] RAN Wuping;CHEN Huimin;HUANG Jianjun;LI Ling;AI Xianchen(School of Architectural Engineering, Xinjiang University, Urumqi 830047, China;Xinjiang Civil Engineering Technology Research Center, Urumqi 830047, China;Urumqi City Construction Design Institute, Urumqi 830000, China)

机构地区：[1]新疆大学建筑工程学院,新疆乌鲁木齐830047 [2]新疆土木工程技术研究中心,新疆乌鲁木齐830047 [3]乌鲁木齐城建设计研究院,新疆乌鲁木齐830000

出　　处：《大连理工大学学报》2021年第2期180-188,共9页Journal of Dalian University of Technology

基　　金：国家自然科学基金资助项目(51768070);新疆大学自然科学基金资助项目(201809).

摘　　要：为明确冻融循环对粗粒土路基力学特性的影响,借助动三轴试验系统,研究了不同含水率、不同应力加载路径和不同冻融循环次数下粗粒土动回弹模量的变化规律,并在此基础上提出粗粒土动回弹模量调整系数及衰变规律的拟合公式.试验结果表明:动回弹模量随着含水率的增加呈现减小的趋势,含水量4%对应的动回弹模量最大,不同含水率之间对应的动回弹模量差值在经过冻融循环作用后不会发生较大的变化;偏应力一定时,围压与动回弹模量呈正相关,围压一定时,偏应力与动回弹模量呈负相关;动回弹模量随着冻融循环次数N的增加整体呈衰减趋势,衰变过程可分为快速衰减(N=0~3)、缓慢衰减(N=3~5)及衰减停止(N=5~7)3个阶段.研究成果可为我国季节性冰冻区公路路基强度设计提供参考依据.In order to clarify the effect of freeze-thaw cycle on the mechanical properties of coarse-grained soil subgrade,the variation of dynamic resilience modulus of coarse-grained soil under different moisture contents,different stress loading paths and different freeze-thaw cycle times is studied by means of dynamic triaxial test system.And on this basis,adjustment factors for dynamic resilience modulus and fitting formula of decay law are proposed for coarse-grained soil.The experimental results show that the dynamic resilience modulus decreases with the increase of moisture content,the dynamic resilience modulus corresponding to 4%of moisture content is the largest,and the difference of dynamic resilience modulus corresponding to different moisture contents will not change greatly after freeze-thaw cycle.When the partial stress is constant,the confining pressure is positively correlated with the dynamic resilience modulus.When the confining pressure is fixed,the partial stress is negatively correlated with the dynamic resilience modulus.The dynamic resilience modulus decreases with the increase of the number N of freeze-thaw cycles.The decay process can be divided into three stages:rapid attenuation(N=0-3),slow attenuation(N=3-5)and attenuation stop(N=5-7).The research results can provide reference for the design of highway subgrade strength in seasonal frozen area of China.

关 键 词：道路工程 粗粒土 动回弹模量 冻融循环 调整系数 

分 类 号：TU443[建筑科学—岩土工程]