基于环剪试验的蠕变型滑坡滑带力学性质——以甘肃舟曲地区锁儿头滑坡为例  

Mechanical Properties of Creep-type Landslide Slip Zone Based on Ring Shear Test-A Case Study of Suo'ertou Landslide in Zhouqu Area of Gansu,China

作　　者：路昌明 王祚鹏 吴靓 权烨孜 宁瑞浩 甘良橙 LU Chang-ming;WANG Zuo-peng;WU Liang;QUAN Ye-zi;NING Rui-hao;GAN Liang-cheng(School of Engineering and Technology,China University of Geosciences,Beijing 100083,China;Qinghai Istitute of Geo-environment Monitoring,Xining 810008,Qinghai,China)

机构地区：[1]中国地质大学(北京)工程技术学院,北京100083 [2]青海省地质环境监测总站,青海西宁810008

出　　处：《地球科学与环境学报》2024年第5期677-688,共12页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(4220071130);中央高校基本科研业务费专项资金项目(590123008)。

摘　　要：蠕变型滑坡的变形与滑带力学性质关联十分紧密,研究不同含水率和不同砾石含量下滑带力学性质变化规律,对理解蠕变型滑坡的变形机制具有重要意义。以甘肃舟曲地区锁儿头滑坡滑带岩土体为研究对象,通过环剪试验探究滑带在不同含水率(15%、19%和22%)、不同砾石含量(0%、5%和15%)和不同剪切速率(0.5、3.0和30.0 mm·min^(-1))下的力学性质变化规律。结果表明:①在长距离剪切下,滑带抗剪强度随含水率的增加而减小,而滑带达到峰值强度所需位移随含水率的增加而增加,同时滑带的残余黏聚力随含水率的升高而显著降低;②滑带抗剪强度随砾石含量的增加而增加;③随着剪切速率的增加,滑带抗剪强度逐渐减小,并且内摩擦角也呈现明显下降趋势。结合区域背景,甘肃舟曲地区锁儿头滑坡的蠕变速率与季节性降雨及断裂活动有关。The deformation of creep-type landslides is closely related to the mechanical properties of the slip zone.Investigating the variations in the mechanical properties of the slip zone under different water contents and gravel contents is crucial for understanding the deformation mechanisms of creep-type landslides.The slip soil of Suo'ertou landslide in Zhouqu area of Gansu was focused on.Through ring shear tests,the variations in the mechanical properties of the slip zone under different water contents(15%,19%and 22%),gravel contents(0%,5%and 15%),and shear rates(0.5,3.0 and 30.0 mm·min^(-1))were explored.The results show that①under long-distance shearing,the shear strength of the slip zone decreases with the increase in water content,while the displacement required to reach peak strength of the slip zone increases with the increase in water content;simultaneously,the residual cohesion of the slip zone significantly decreases with the increase in water content;②the shear strength of the slip zone increases with the increase in gravel content;③as the shear rate increases,the shear strength of the slip zone gradually decreases,and the internal friction angle also shows a significant decreasing trend.Combining regional background information,it is suggested that the creep rate of Suo'ertou landslide in Zhouqu area of Gansu is related to seasonal rainfall and fault activities.

关 键 词：滑坡 滑带 环剪试验 含水率 砾石含量 剪切速率 残余强度 甘肃 

分 类 号：P642.22[天文地球—工程地质学]