粗粒土体变规律大型三轴试验研究  

Large-scale triaxial test study on volumetric strain law of coarse-grained soil

作　　者：孟飞[1] 张家生[1] 胡奇凡[2] 陈晓斌[1] 王启云[1] 

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]铁道第三勘察设计院集团有限公司,天津300251

出　　处：《水利水电技术》2013年第6期139-142,146,共5页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金资助项目(NO.50908233);国家工程实验室基金资助项目(2008G031-Q)

摘　　要：采用粗粒土大型三轴剪切仪,对饱和粗粒土进行固结排水剪切试验,提出了拟合三轴剪切试验中轴向应变与侧向应变的函数方程,利用此关系式对三轴试验中试样的体积应变进行了预测。预测结果表明:改进模型能合理地描述粗粒土的体积应变规律,尤其是高围压下剪缩、低围压下剪胀的特性。由体积应变方程导出以轴向应变为自变量的切线泊松比表达式,通过与邓肯张模型及由数值方法求得的切线泊松比对比,讨论了该表达式的合理性。Based on large-scale triaxial shearing apparatus, the consolidated-drained shear tests on the saturated coarsegrained soil are conducted, and then a function for fitting the axial strain and lateral strain in the triaxial test is put forward ; by which the volumetric strain of the soil-sample in the test is predicted. The prediction shows that the modified model can reasonably describe the volumetric strain law of the coarse-grained soil, especially the characteristics of the sample that dilates under the lower confining pressures and contracts under higher confining pressure. Whereafter, a tangent poission＇ s ratio expression that takes axial strain as independent variable is derived from the volumetric strain equation, and its rationality is discussed through the comparison with both Duncan-Chang model and the tangent poission＇ s ratio obtained by the numerical method concerned.

关 键 词：粗粒土 大型三轴试验 剪胀 体积应变 

分 类 号：TU443[建筑科学—岩土工程]