压实粘性土动态力学性能的SHPB试验  

SHPB Experiment of Dynamic Mechanical Behavior of Compacted Clay

作　　者：刘俊新[1,2] 陈忠富[1] 徐伟芳[1] 何鹏[1] 

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

出　　处：《西南交通大学学报》2011年第6期960-965,共6页Journal of Southwest Jiaotong University

基　　金：国家973计划资助项目(2010CB832700)

摘　　要：为解决因土体波阻抗及波速较低且变形较大,采用传统的分离式Hopkinson压杆(SHPB)实验装置不能准确获得土体的动态应力-应变曲线的问题,采用直径25 mm的聚碳酸脂SHPB实验装置和真空封泥小球丸作为波形整形器,以不同的轴向速度撞击试件,测试试件在应变率600～2 500 s-1之间的动态力学性能,并通过应力平衡和常应变率分析对试验结果的有效性进行了讨论.结果表明:用聚碳酸脂SHPB装置对压实粘性土进行动态试验是可行的;土体的动态应力与应变具有显著的应变率效应,动态应力与应变率成指数关系.Because of soils＇ low wave velocity and impedance and large deformation, it is unable to obtain their reliable and accurate dynamic stress-strain curves with a conventional SHPB （split Hopkinson pressure bar） experimental device. To investigate the compressive mechanic properties of compacted clays under strain rates varying from 600 to 2 500 s^-1, compacted clay specimens were subjected to axial impact with different projectile speeds by using the improved SHPB with a diameter of 25 mm made of polycarbonate and a small pellet of vacuum seal cement as pulse shaper, and the validity of the experiment was discussed by considering the stress equilibrium and constant strain rate. The results show that the polycarbonate SHPB device can be used to the dynamic experiment of compacted clays, the dynamic stress and strain of a compacted clay are sensitive to strain rate, and the relationship between dynamic stress and strain rate may be expressed by an exponential function.

关 键 词：聚碳酸脂 压实粘性土 波形整形技术 高应变率 动态力学性能 

分 类 号：TU411.8[建筑科学—岩土工程]