压实度和含水率对压实黏性土动态力学性能的影响试验研究  

Experimental study of dynamic properties of compacted clay under different compaction degrees and water contents

作　　者：刘俊新[1,2] 陈忠富[2] 徐伟芳[2] 陈刚[2] 

机构地区：[1]西南科技大学土木与建筑学院,四川绵阳621010 [2]中国工程物理研究院总体工程研究所,四川绵阳621900

出　　处：《岩土力学》2012年第6期1631-1639,共9页Rock and Soil Mechanics

基　　金：国防973项目(No.61392);国家青年科学基金(No.11002134;No.11102195)

摘　　要：利用直径为φ25 mm的聚碳酸脂分离式SHPB试验装置和真空封泥作为波形整形器,以不同速度撞击试件,测试了不同压实度和含水率试件在应变率范围为600～2 500 s-1内的动态力学性能,并对试验结果的有效性进行了讨论,分析了冲击压缩荷载作用下应力-应变曲线、动态峰值应力与峰值应变,动态峰值应力和峰值应变增长因子以及比能量吸收与应变率之间的关系。研究结果表明:压实黏性土的动态峰值应力、峰值应变和比能量吸收随应变率的增大而增大,而压实度与含水率对压实黏性土的动态峰值应力、峰值应变和比能量吸收基本无影响;压实度与含水率对动态峰值应力和峰值应变增长因子有较大影响;比能量吸收随应变率而呈指数增长。In order to investigate compression mechanical properties with strain rates varying from 600 s-1to 2 500 s-1on compacted clays under different compaction degrees and water contents,the specimens are subjected to axial impact with different projectile speeds by using the split Hopkinson pressure bar（SHPB） of 25 mm in diameter made by polycarbonate and a small pellet of vacuum seal cement as pulse shaper;and the validity of experiment is discussed considering the stress equilibrium and constant strain rate.The related curves of stress and strain,the relationship between dynamic stress and strain at peak with strain rates,the relationship between dynamic stress increase factor and strain increase factor at peak with strain rates,and what’more,the relationship between specific energy absorption and strain rates are also analyzed.Experimental results show that the dynamic peak stress,peak strain and specific energy absorption increase with the increase of strain rate;but the compaction degrees and the water contents have no influence on them;compaction degrees and water contents have a greater influence on dynamic stress increase factor and strain increase factor at peak;specific energy absorptions are dependent on strain rates;and the strain rate effect can be expressed by exponential approximations.

关 键 词：压实度 含水率 动态力学 应变率 比能量吸收 

分 类 号：TU45[建筑科学—岩土工程]