循环荷载下土石混合体力学特性野外试验研究

FIELD HORIZONTAL PUSH SHEAR TEST FOR MECHANICAL PROPERTY OF SOIL-ROCK MIXTURES UNDER CYCLIC LOADING

土石混合体是一种物理、力学性质非常复杂的不连续介质。以云南某高速公路土石混合体边坡为例,分别对选取的3个试验点进行了单调加载、循环加载一次及多次循环加载试验,获取了其相应的剪切位移-剪切应力关系曲线,并对其曲线特征进行分析研究。通过对试样三维滑动面的形态分析,指出由于土石混合体三维滑动面的不规则性,利用传统的二维计算方法难以得到较为准确的强度参数。基于三维极限平衡理论,提出了土石混合体水平推剪试样强度参数的三维数据计算方法。并利用该方法得到了研究区土石混合体的相应的强度参数及残余强度参数。

Soil - Rock mixture （ S - RM ） is a kind of inhomogeneous geomaterial. Taking a Yunnan highway S - RM slope as an example, horizontal push - shear tests under loading and unloading conditions were preformed to three selected samples. Then the curves of shearing strength versus displacement of these three samples were received. Studies were performed to the characteristics of these curves. Through the analysis of the samples＇ sliding surface under three - dimension, it seems that it is inaccurately to calculate the strength parameters of S - RM for the scrambling of the three -dimension sliding surface. Based on the three limit -equilibrium theory, the method of calculating the strength parameters of S - RM under three - dimension condition were put forward. Using this method, the strength parameters and the residual strength parameters of S - RM in the study area were received. These parameters can be very important to evaluate slopes.