甘肃舟曲江顶崖滑坡堆积层剪切特性与强度参数分析  

Analysis of shear characteristics and strength parameters in Jiangdingya landslide,Zhouqu County

作　　者：张卫雄 杨校辉[3] 丁保艳[1,2] 朱文杰 任永忠[4] ZHANG Weixiong;YANG Xiaohui;DING Baoyan;ZHU Wenjie;REN Yongzhong(Gansu Geological Disaster Prevention Engineering Exploration and Design Institute,Lanzhou,Gansu 730050,China;Third Institute Geological and Mineral Exploration of Gansu Provincial Bureau of Geology and Mineral Resources,Lanzhou,Gansu 730050,China;School of Civil Engineering,Lanzhou University of Technology,Lanzhou,Gansu730050,China;School of Civil Engineering,Lanzhou Institute of Technology,Lanzhou,Gansu 730050,China)

机构地区：[1]甘肃地质灾害防治工程勘查设计院,甘肃兰州730050 [2]甘肃省地矿局第三地质矿产勘查院,甘肃兰州730050 [3]兰州理工大学土木工程学院,甘肃兰州730050 [4]兰州工业学院土木工程学院,甘肃兰州730050

出　　处：《中国地质灾害与防治学报》2025年第1期65-72,共8页The Chinese Journal of Geological Hazard and Control

基　　金：甘肃省科技重大专项(23ZDFA007);甘肃省地质矿产勘查开发局创新基金项目(2020CX09,2022CX13);甘肃省自然资源厅科技创新项目(202222);甘肃省教育厅青年博士基金项目(2021QB-126)。

摘　　要：研究古滑坡中堆积层的强度特性是进行滑坡稳定性验算及其防治的重要环节,为合理确定古滑坡堆积层稳定性分析中的强度参数,依托甘肃舟曲江顶崖古滑坡治理工程,以滑体土(碎石土)、滑带土(含砾黏土)为研究对象,分别取2个典型地段采用平推法进行现场大型剪切试验。将试验结果与基于工程类比法的力学参数建议值进行了对比分析,结果发现:(1)滑带土剪切应变较小时,剪应力-剪切位移关系曲线有交叉现象,土样的剪应力随正应力与剪应变的增大呈现递增;(2)滑体土正应力越大,应变软化表现得越明显;(3)滑坡土的残余强度较峰值强度有一定衰减,但主要表现为黏聚力的减弱,其内摩擦角几乎没有变化,是因为在滑体土发生剪切后,滑带土中的胶结物被破坏,胶结作用减弱;泄流坡滑体土的天然残余强度参数内摩擦角在18.2°到24.6°之间,黏聚力在10.2 kPa到12.4 kPa之间,滑体土的残余强度参数与工程类比值得到的参数更加接近;(4)舟曲江顶崖堆积层滑坡滑带土和滑体土的岩体力学参数建议值:滑带土黏聚力7.0~14.8 kPa,内摩擦角15.0°~17.5°;滑体土黏聚力15.8~30.9 kPa,内摩擦角23.9°~24.4°。Studying the strength characteristics of the accumulation layer in ancient landslides is an important aspect of landslide stability analysis and control.In order to reasonably determine the strength parameters in the stability analysis of ancient landslide accumulation layers,this study focuses on the Jiangdingya ancient landslide treatment project in Zhouqu County,Gansu Province.The study targets the the sliding body soil(gravel soil)and sliding zone soil(gravelly clay)and conducts large-scale field shear tests at two typical sections using the horizontal pushing method.The test results are compared and analyzed with the suggested mechanical parameters based on engineering analogy method.Based on the above research,the following conclusions are drawn:(1)When the shear strain of the sliding zone soil is small,the shear stress-shear displacement relationship curve has crossed,and the shear stress of the soil sample increases with the increase of normal stress and shear strain;(2)The larger the normal stress of the sliding body soil,the more significant the strain softening behavior;(3)The residual strength of the landslide soil has a certain attenuation compared to the peak strength,mainly manifested as a weakening of cohesion,while the internal friction angle remains almost unchanged.This is because the cementitious material in the sliding zone soil is destroyed after shear deformation,leading to a weakening of cementation.The natural residual strength parameters of the sliding body soil on the discharge slope are:the internal friction angle ranges from 18.2°to 24.6°,and the cohesion ranges from 10.2 kPa to 12.4 kPa.The residual strength parameters of the sliding body soil are closer to the values obtained by the engineering analogy method;(4)The recommended values of rock mass mechanical parameters for the sliding zone soil and sliding body soil of the accumulation layer landslide at Jiangdingya are as follows:For the sliding zone soil,the cohesion ranges from 7.0 kPa to 14.8 kPa,and the internal friction angl

关 键 词：古滑坡 堆积体 原位剪切试验 抗剪强度 残余强度 

分 类 号：P642.22[天文地球—工程地质学]