结构性土中剪切带扩展的模型试验研究  

Experimental study of the evolution of shear bands in structured soil

作　　者：喻葭临[1] 孙逊[1] 于玉贞[1] 柴霖[1] 

机构地区：[1]清华大学水利水电工程系,水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《清华大学学报（自然科学版）》2010年第3期367-371,共5页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(50779024,50879039,50639060)

摘　　要：使用自行研制的土工压力室模型箱,进行了模型试验,以考察人工制备结构性土中已有剪切带的扩展规律。试验结果表明:预设剪切带的存在使剪切带并没有突然贯穿整个研究区域,而是存在一个扩展的过程,即剪切带前端区域内的位移场经历了从均匀变形到弱不连续再到强不连续的渐进过程。分析表明:已有剪切带尖端附近区域存在应力集中和应力重分布现象,并进而导致剪切带尖端附近区域的应力主轴偏转。A series of model tests were performed to investigate the mechanism for the evolution of shear band preset in artificial structured soil samples using a geotechnical test apparatus. The results show that the shear band is a progressive process rather than an abrupt failure due to the shear band preset, and the displacement field around the tip varies from uniform deformation to weak discontinuity and then strong discontinuity. Further analysis reveals that stress concentration and redistribution exist around the tip of the shear band preset, which then causes stress axes deflection in the tip area.

关 键 词：剪切带 模型试验 应力集中 应力主轴偏转 

分 类 号：TU411.93[建筑科学—岩土工程]