无法向荷载推剪试验的解析与应用  

Analysis of push shear test without normal loading and its application

作　　者：张年学[1] 李晓[1] 赫建明[1] 顾金略[1] 

机构地区：[1]中国科学院地质与地球物理研究所工程地质力学重点实验室,北京100029

出　　处：《岩土力学》2010年第3期863-869,共7页Rock and Soil Mechanics

基　　金：国家重点基础研究发展计划(973)(No2009CB724605;2010CB731501);中国科学院知识创新工程重要方向项目(NoKJCX3-SW-L1);中国科学院科研装备研制项目(NoYZ200912)

摘　　要：推剪试验常在滑坡现场勘探中采用,获取抗剪强度。工程地质手册中推剪试验的现有数据分析处理方法存在一些缺点,应加以改进。研究无法向荷载刚体模型的推剪试验数据处理方法,假设模型受压面在Y轴方向不受约束。推导出该模型推剪试验的微分方程,解析出求c、φ值与破坏面曲线方程组公式。根据原位试验发生的压缩现象,分析了试体受压面附近存在局部先期破坏。对新公式进行了算例与实例的分析,解释了影响破坏面曲线变形的原因是:推剪受压面必须满足Y方向不受约束,该面应安装能垂直滑动或转动的承压板。对受压面被约束的试验,可根据局部破坏面斜率推测破坏体长度,进行c、φ值计算。此外,还提出了推剪试验必须注意的几个问题。Push shear tests have often been used to determine shear strength of rocks or soils in investigation of landslides. However current analytical methods for a push shear test recommended in Handbook of Engineering Geology could not adequately derive parameters of the shear strength and should be improved. Data processing method is presented for the push shear test without normal loading based on the assumption of model＇s rigid body and no constraints along Y axis. A differential equation is established to represent the push shear test; and a set of equations is then derived for solving cohesion c, friction angle φ and curves of the shear failure surface. A case study is used to examine new formulas developed. Based on observed compression phenomena during in-situ test, the localized initial failure near the compression surface is analyzed. Causes for variation of the shear failure surface are explained. It is required that no constraints are applied to the compression surface along Y axis. In addition, the compression surface should he oriented perpendicular to the sliding or rotating surface. At the end, several issues related to push shear test are also discussed.

关 键 词：推剪试验 解析 应用 抗剪强度 破坏面曲线 

分 类 号：O24[理学—计算数学]