不同浸水时长滑带土的力学特性与微观结构研究  

Study on Mechanical Properties and Microstructure of Sliding Zone Soils Under Different Immersion Duration

作　　者：周春梅 秦子寒 吴雪华 朱锐 柴修伟[2] ZHOU Chunmei;QIN Zihan;WU Xuehua;ZHU Rui;CHAI Xiuwei(School of Civil Engineering and Architecture,Wuhan Institute of Technology,Hubei Wuhan 430074,China;School of Resources and Security Engineering,Wuhan Institute of Technology,Hubei Wuhan 430074,China)

机构地区：[1]武汉工程大学土木工程与建筑学院,湖北武汉430074 [2]武汉工程大学资源与安全工程学院,湖北武汉430074

出　　处：《防灾减灾学报》2025年第1期17-26,64,共11页Journal of Disaster Prevention And Reduction

基　　金：国家自然科学基金项目(41002112);湖北省教育厅科学技术研究项目(Q20151511);武汉工程大学校研究生教育创新基金(2020124)。

摘　　要：三峡库区蓄水使得库岸滑坡前缘土体长期处于浸泡状态,土体由于浸水软化而影响滑坡稳定性。以三峡库区石龙门滑坡滑带土为研究对象,对滑带土进行浸水试验,从物理与化学角度研究不同浸水时长对滑带土力学特性和微观结构的影响,并提出了三者相互关系的多元回归模型。结果表明:(1)随着浸水天数的增加,滑带土的峰值强度劣化明显,前3天土体强度衰减幅度达到了79%,之后衰减幅度减弱并趋于平缓,粘聚力劣化效应大于内摩擦角;(2)滑带土浸水后以叠片状为主的土体颗粒逐渐解体,颗粒孔隙增大,颗粒间连接方式由面-面转化为边-边连接,颗粒的边角逐渐转化为圆弧、圆边形态,颗粒圆润度与内摩擦角相关系数为-0.996,孔隙形态比与弹性模量相关系数为0.963;(3)滑带土浸水后经化学反应,碎屑矿物逐渐向粘性矿物转化,粘性矿物吸水膨胀、失水收缩引发土颗粒、孔隙及胶结物等微观结构变化是滑带土力学特性劣化的内在原因。研究结果可为库岸滑坡浸水后稳定性分析提供数据参考。The water storage in the Three Gorges Reservoir area has caused the soil at the forefront of the reservoir bank landslide to be soaked for a long time,affecting the stability of the landslide due to the softening of the soil by soaking.Taking the slip zone soil of the Shilongmen landslide in the Three Gorges Reservoir area as the research object,a soaking test was conducted on the slip zone soil.The effects of different soaking durations on the mechanical properties and microstructure of the slip zone soil were studied from a physical and chemical perspective,and a multiple regression model of their interrelationships was proposed.The results show:(1)As the soaking days increase,the peak strength of the slip zone soil deteriorates significantly.The strength of the soil decreases by 79%in the first three days,and then the rate of decrease slows down and tends to stabilize.The deterioration effect of cohesion is greater than that of the internal friction angle.(2)After the slip zone soil is soaked,the soil particles,which are mainly in a laminated form,gradually disintegrate.The particle pores enlarge,and the contact mode between particles changes from face-to-face to edge-to-edge.The edges and corners of the particles gradually transform into arcs and rounded shapes.The correlation coefficient between particle roundness and internal friction angle is-0.996,and the pore shape ratio and elastic modulus correlation coefficient is 0.963.(3)After the slip zone soil is soaked,it undergoes a chemical reaction.The detrital minerals gradually transform into cohesive minerals.The swelling of cohesive minerals due to water absorption and shrinkage due to water loss cause changes in the microstructure of soil particles,pores,and binders,which is the intrinsic reason for the deterioration of the mechanical properties of the slip zone soil.The research results can provide data references for the stability analysis of reservoir bank landslides after soaking.

关 键 词：三峡库区 滑带土 力学特性 微观结构 回归分析 

分 类 号：P642.22[天文地球—工程地质学] X43[天文地球—地质矿产勘探]