摘要
滑坡地下水环境的变化对滑带土的强度和变形参数有着极大的影响,并影响滑坡的稳定性。三峡库区受到库水位升降及降雨入渗的影响,使得发育于该地区滑坡的滑带土含水率及离子浓度一直处于不断的变化中。以重庆万州区兴福寺滑坡为例,针对滑带土重塑样,采用X射线衍射分析了其矿物成分,然后进行了不同含水率下固结排水直剪试验、不同SO_4^(2-)离子浓度下滑带土的固结排水慢剪试验以及不同SO_4^(2-)离子浓度下滑带土直剪反复剪切试验。试验结果表明:滑带土成分以黏土矿物、石英、钠长石等为主,其中黏土矿物以伊蒙混层、伊利石为主;含水率对滑带土抗剪强度指标的影响较为明显,具体为黏聚力随含水率的增大而增大,内摩擦角随含水率的增大而减小;SO_4^(2-)离子浓度对滑带土抗剪强度指标的影响也较为显著,随着SO_4^(2-)离子浓度的增大,黏聚力与内摩擦角均减小;滑带土经过反复剪切后,残余强度、黏聚力和内摩擦角均随着SO_4^(2-)离子浓度的增大而减小。
The change of ground water environment in the slide zone soil has a great influence on the strength and deformation parameters,and affects the stability of the landslide.The Three Gorges Reservoir area is affected by the rise and fall of reservoir water level and rainfall infiltration,and this changes the water content and ion concentration of the landslides soil in this area constantly.Taking the Xingfusi landslide in Wanzhou area in Chongqing as an example,this paper uses the X ray diffraction to analyse the mineral composition of the remolded samples from the sliding zone soil and performs the direct shear test on the samples with different water content at consolidated drain condition.Next the direct slow shear test and repeated shear test were conducted on the samples with different SO42-ion concentration respectively.The test results show that the composition of the sliding-zone soil is dominated by clay minerals,quartz,albite,etc.,and the clay minerals are mainly composed of illite mixed layer and illite.The influence of water content on the shear strength index of sliding zone soil is more obvious.Specifically,the cohesion increases with water content,while the inner friction angle decreases with water content.The influence of SO42-ion concentration on the shear strength index of sliding zone soil is also significant.With the increaseof SO42-ion concentration,both the cohesion and the inner friction angle decrease.From the repeated shearing of the sliding belt soil,we can find that the residual strength,cohesion,and internal friction angle all decrease with the increase of SO42-ion concentration.
作者
刘虎虎
缪海波
陈志伟
黄金勇
Liu Huhu;Miao Haibo;Chen Zhiwei;Huang Jinyong(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan Anhui 232001,China)
出处
《地质科技情报》
CAS
CSCD
北大核心
2019年第1期228-234,共7页
Geological Science and Technology Information
基金
国家自然科学基金项目(41502335)
中国博士后科学基金项目(2016M592032)
关键词
滑带土
含水率
抗剪强度
SO42-离子浓度
残余强度
sliding zone soil
water content
shear strength
SO42- ion concentration
residual strength
作者简介
刘虎虎(1992—),男,现正攻读土木工程专业硕士学位,主要从事边坡及滑坡工程方面的研究工作。E-mail:281054459@qq.com;通信作者:缪海波(1985—),男,副教授,主要从事岩土体稳定性及地质灾害方面的教学与研究工作。E-mail:hbmiao@aust.edu.cn.
