基于原位推剪试验的露天矿边坡土石混合体力学特性分析  

Study on Mechanical Properties of Soil-rock Mixture in Open-pit Slope based on In-situ Push Shear Test

作　　者：李梅华[1] LI Meihua(Yellow River Conservancy Technical Institute,Kaifeng 475004,China)

机构地区：[1]黄河水利职业技术学院

出　　处：《矿业安全与环保》2019年第5期21-24,31,共5页Mining Safety & Environmental Protection

基　　金：国家自然科学基金项目(40972171)

摘　　要：为了研究矿山边坡滑坡段土石混合体的力学特性,对山西省平朔露天矿边坡滑坡段的6处不同高程的土石混合体开展大型原位推剪试验,获取原位剪切强度指标,并研究了含石量对剪切强度指标的影响。研究结果表明:由原位推剪试验得到不同高程的应力—应变曲线都经过了初始变形、弹塑性变形和应力软化变形3个阶段;随着试验点高程的增加,曲线整体沿着纵坐标上移,峰值强度明显增大;各高程试样的黏聚力随着高程的减小而逐渐增大,内摩擦角随高程的减小而逐渐减小;在含石量较低和较高的情况下,黏聚力随含石量增加有小幅下降,而含石量在35.6%~50.0%内时,黏聚力与含石量呈正相关关系;内摩擦角与含石量保持明显的正相关线性关系。试验结果可为矿山滑坡体的稳定性计算提供真实有效的原位力学参数。In order to study the mechanical properties of the soil-rock mixture in the landslide section of mine slope,in-situ push shear tests in large scale were carried out on the soil-rock mixture at 6 different elevations in the landslide section of Pingshuo open-pit mine slope in Shanxi Province.Index of in-situ shear strength was obtained and the effect of rock content on the index was studied.The results show that the stress-strain curves at different elevations obtained by in-situ shear tests have undergone three stages:initial deformation,elastic-plastic deformation and stress-softening deformation;as the elevation of the test site increases,the curve moves up along the y-coordinate and the peak intensity increases obviously;with the decrease of elevation,the cohesion increases and the internal friction angle decreases;the cohesion decreases slightly with the increase of the rock content at the lower and higher rock content stages,when the rock content is from 35.6%to 50.0%,the cohesion is positively correlated with the stone content;the internal friction angle is positively correlated with the rock content.The test results can provide real and effective in-situ mechanical parameters for the stability calculation of the mine landslide.

关 键 词：露天矿边坡 滑坡 土石混合体 原位推剪试验 黏聚力 内摩擦角 

分 类 号：TD325.1[矿业工程—矿井建设] TU41[建筑科学—岩土工程]