含一阶和二阶起伏体节理剪切强度的试验研究  

EXPERIMENTAL STUDY OF SHEAR STRENGTH OF JOINTS WITH FIRST-ORDER AND SECOND-ORDER ASPERITIES

作　　者：朱小明[1,2] 李海波[1] 刘博[1] 邹飞[1] 莫振泽[1] 杨风威[1] 郝亚飞[1] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]甘肃省交通规划勘察设计院有限责任公司,甘肃兰州730000

出　　处：《岩石力学与工程学报》2011年第9期1810-1818,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家杰出青年科学基金项目(51025935);国家重点基础研究发展计划(973)项目(2010CB732001);国家自然科学基金面上项目(40872188)

摘　　要：利用高强石膏材料浇注含不同一阶和二阶起伏度的岩体节理模拟试件,通过节理在不同一阶和二阶起伏度及法向应力下的常法向荷载剪切试验,对其剪切强度特性进行研究,分析一阶和二阶起伏度及法向应力对剪切强度的影响规律。试验结果表明:含二阶起伏体节理试件的剪切强度-剪切位移曲线有多个峰值剪应力出现,只含一阶起伏体节理的峰值剪应力不明显;节理剪切强度随着一阶和二阶起伏度及法向应力的增大而增大;随着二阶起伏度与一阶起伏度比值的增大,剪切强度先增大后降低。对试验数据进行回归分析,提出能反映一阶和二阶起伏度及法向应力影响的剪切强度经验公式。Simulated rock joint samples with different first-order and second-order asperity heights are casted by high strength gypsum material.A series of CNL（constant normal load） shear tests are carried out to study the shear strength characteristics of joints with different first-order and second-order asperity heights under different normal stresses.The influences of first-order and second-order asperity heights and normal stress on shear strength are analyzed.Based on the experimental results,it can be found that the joint samples with second-order asperity have multi-peak shear stresses,while the joint samples only with first-order asperity have not apparent peak shear stress.The shear strength increases with the increasing first-order and second-order asperity heights and normal stress.With the increasing ratio of second-order asperity height to first-order asperity height,shear strength first increases and then decreases.Finally,an empirical formula is proposed by regression analysis of experimental data to predict the shear strength.The formula can reflect the influences of first-order and second-order asperity heights and normal stress on shear strength.

关 键 词：岩石力学 岩体节理 剪切强度 二阶起伏体 

分 类 号：TU45[建筑科学—岩土工程]