南方湿热地区路基红黏土Shakedown临界应力水平试验研究

发布时间：2019-01-26 20:21

【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。
[Abstract]:According to the climate characteristics of the southern humid and hot areas and the calculation of the stress of 10 typical freeway subgrade, the dynamic triaxial test scheme of the red clay of the roadbed under repeated load is established. The plastic mechanical behavior of subgrade red clay under different compaction, moisture content, axial stress level and cyclic loading times was studied. Combining with the concept of Shakedown, the Shakedown critical stress level of red clay under cyclic dynamic load was defined. The results show that the compaction degree has little effect on the critical stress level of red clay, and the water content has a significant effect on it. The critical stress levels corresponding to the optimum water content Com and 110ComC120Com and 130%Com are 70% and 40%, respectively. Based on this, the Shakedown critical stress envelope of subgrade red clay can be drawn in the humid and hot area of southern China. In design, the critical stress level corresponding to the construction moisture content should be taken as the upper limit of the subgrade force, so as to ensure the stability and durability of the subgrade deformation.
【作者单位】：长沙理工大学公路养护技术国家工程实验室;
【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)
【分类号】：U416.1

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