含二阶起伏体的模拟岩体节理试样剪切特性试验研究  

Experimental study of shear characteristics by simulating rock mass joints sample with second-order asperities

作　　者：朱小明[1,2] 李海波[1] 刘博[1] 邹飞[1] 莫振泽[1] 宋全杰[1] 牛磊[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,武汉430071 [2]甘肃省交通规划勘察设计院有限责任公司,兰州730030

出　　处：《岩土力学》2012年第2期354-360,共7页Rock and Soil Mechanics

基　　金：国家杰出青年基金资助项目(No.51025935);国家重点基础研究发展计划(973)项目(No.2010CB732001);国家自然科学基金资助项目(No.40872188)

摘　　要：利用规则的小尺寸锯齿构造二阶起伏体,对不同二阶起伏体高度的人工节理进行常法向应力下的直剪试验,研究了节理剪切力学特性。对节理的剪切强度、变形特征进行了分析,并对破坏特征做出解释。试验结果表明:二阶起伏体对节理剪切力学特性有重要影响,含二阶起伏体节理的剪切力学特性与只含有一阶起伏体节理的剪切力学特性不同,只含一阶起伏体的节理剪应力只有一个峰值,含二阶起伏体的节理会出现波浪状的剪胀曲线和多峰值剪应力,且峰值剪应力随剪切位移增大依次出现并逐个减小;随着二阶起伏体高度增大,节理峰值剪切强度增大,节理依次出现磨损破坏、多次性剪断破坏、一次性剪断破坏。The monotonic shear tests are carried out to investigate the mechanical properties of rock mass joints with the second-order asperities,which simulated by small regular saw tooth;and gypsum material is used to simulating rock mass joint samples.Five artificial joint samples with different heights of second-order asperities are tested under low normal stress,which keep constant during the tests.Characteristics of shear strength and deformation are analyzed;an interpretation of the joints failure modes is given.Based on the experimental results,it can be found that the second-order asperities have important influence on the shear mechanical properties of joints,and the mechanical properties are different from the joints with first-order asperities only,for which shear stress vs.shear displacement curve just has one peak shear stress;by contrast,the joints with second-order asperities have multi-peak shear stress,which decreases gradually one after one with the increase of shear displacements.As well,the dilatancy curves of the joints with second-order asperities show wave shape.With the increase of second-order asperities height,peak shear strength increases;the failure modes appear wearing,many-times shearing of asperities,and one-time shearing failure of asperities.

关 键 词：岩石力学 节理 二阶起伏体 剪切特性 剪应力 剪胀 

分 类 号：TU452[建筑科学—岩土工程]