南方湿热地区路基红黏土Shakedown临界应力水平试验研究  

Research on critical stress level of Shakedown of red clay in southern hot and humid areas

作　　者：张军辉[1] 尹志勇[1] 郑健龙[1] 

机构地区：[1]长沙理工大学公路养护技术国家工程实验室,湖南长沙410004

出　　处：《中南大学学报（自然科学版）》2014年第4期1288-1292,共5页Journal of Central South University:Science and Technology

基　　金：国家重点基础研究发展计划("973"计划)项目(2011CB411910);国家高技术研究发展计划("863"计划)项目(2012AA112504);国家自然科学基金资助项目(51108048);交通运输部道路结构与材料行业重点实验室开放基金资助项目(kfj110202)

摘　　要：根据南方湿热地区气候特点和10条典型高速公路路基受力计算,制定路基红黏土的重复荷载动三轴试验方案;研究不同压实度、含水率、轴向应力水平、循环加载次数等条件下路基红黏土的塑性力学行为,并结合Shakedown概念,界定循环动荷载作用下红黏土的Shakedown临界应力水平。研究结果表明:压实度对红黏土临界应力水平影响较小,含水率对其影响显著,最佳含水率Com及110%Com,120%Com和130%Com对应的临界应力水平分别为70%,70%,60%和40%,据此可绘制南方湿热地区路基红黏土Shakedown临界应力包络线;设计时,应以施工含水率对应的临界应力水平作为路基受力的控制上限,从而保证路基的变形稳定和耐久性。According to the climatic features and subgrade stress state of 10 typical expressways in southern hot and humid areas, a triaxial test plan with a dynamic load of red clay in southern humid and hot areas was made. Based on the Shakedown concept, various mechanical behaviors of subgrade red clay were discussed using repeated loading tests. The tests were performed under various conditions of subgrade soil, including different water contents, stress levels and numbers of repeated loadings. The results show that the water content has more important influence on the critical stress level of Shakedown of red clay than the compaction degree and they are 70%, 70%, 60% and 40% with the increase of the water content, respectively, and the envelope line of critical stress level of Shakedown of red clay can be gained. The subgrade stress should be controlled below the critical stress level which is corresponded to the construction water content to keep the subgrade deformation stable and durable.

关 键 词：南方湿热地区 路基红黏土 Shakedown临界应力 重复荷载三轴试验 

分 类 号：U416.12[交通运输工程—道路与铁道工程]