大光包滑坡层间错动带岩体剪切特性研究  

SHEAR BEHAVIORS OF ROCK MASS IN THE INTERLAYER FAULT ZONE OF DAGUANGBAO LANDSLIDE

作　　者：孟祥瑞 裴向军[1] 黄润秋[1] 崔圣华 朱凌 詹威威 MENG Xiangrui;PEI Xiangjun;HUANG Runqiu;CUI Shenghua;ZHU Ling ;ZHAN Weiwei(State Key Labratory of Geo-hazard Prevention and Geo-environment Protection,Chengdu University of Technology,Chengdu 610059)

机构地区：[1]地质灾害防治与地质环境保护国家重点试验室(成都理工大学),成都610059

出　　处：《工程地质学报》2018年第2期309-318,共10页Journal of Engineering Geology

基　　金：国家重点研究计划(2017YFC1501000);强震山区特大地质灾害致灾机理与长期效应研究;国家自然科学基金项目(41572302);国家自然科学基金创新研究群体项目(41521002)资助

摘　　要：大光包滑坡滑带发育于构造作用形成的层间错动带中,带中岩体由上而下碎裂化程度增加,且底部存在一层泥化带。本研究选取大光包滑坡层间错动带中不同层位的碎裂岩体,共计进行18组中剪试验;此外,选取错动带中泥化带及临近的糜棱质带岩体进行了不同含水率下的42组快剪试验。试验结果表明:层间错动带碎裂岩体的剪切特性同碎裂程度有关,碎裂程度较低的岩体应变软化特性更明显,碎裂程度较高的岩体抗剪强度则更差;糜棱质带土体抗剪强度和内摩擦角一般大于泥化带土体,且剪切特性受地下水的影响小于泥化带;泥化带土体的抗剪强度和黏聚力随含水率的升高迅速降低,其内摩擦角与含水率呈负相关的指数关系,在地震过程中,随着岩体扩容引起地下水入侵,泥化带的抗剪强度会大大降低。研究结果对理解大光包滑坡滑面发育层位和地震中含水率上升及错动带岩体进一步碎裂化对滑带岩体抗剪强度的影响有重要意义。The slide surface of Daguangbao landslide is developed in the interlayer fault zone where the fragmentation degree of rock mass is increased from the upper to the lower with a belt of mud at the bottom.18 groups of medium-sized direct shear tests were carried out for the samples collected from Daguangbao interlayer fault zone.42 groups of unconsolidated direct shear tests were carried for the samples collected from mud belt and mylonite belt by controlling the moisture content.The results show that the shear characteristics of the rock mass in interlayer fault zone are related to the degree of fragmentation.Characteristics of strain softening of rock mass with lower degree of fragmentation is more obvious while the shear strength of rock mass with higher degree of fragmentation is worse.The shear strength and the friction angle of mylonite are mostly greater than the soil in the mud belt and the shear characteristics of mylonite is less affected by the ground water than the mud.The shear strength and cohesive strength of the soil in the mud belt are decreased rapidly with the increase of moisture content.The internal friction angle has a negative exponential relation with the moisture content.The shear strength of the soil in mud belt can be greatly reduced with the intrusion of groundwater caused by the rock mass dilatancy during the earthquake.The results of this study are important for understanding the position of the slip surface.It is also important for understanding the influence of the increase of moisture percentage and the further fragmentation on the shear strength of the rock mass in the fault zone.

关 键 词：大光包滑坡 层间错动带 剪切特性 碎裂程度 含水率 

分 类 号：P642.22[天文地球—工程地质学]