摘要
为了便于研究不同粗糙度结构面岩体在压剪荷载作用下的剪切强度、剪切变形等力学特性的变化规律,制作了3种具有不同起伏高度的大理岩规则齿形结构面,锯齿高度分别为0、1、3 mm,开展了不同法向应力下的结构面直剪试验。试验结果发现,结构面剪应力-剪切位移曲线可分为两类:滑动破坏型和峰值剪断型;结构面沿锯齿先爬坡后剪断的破坏过程可划分为4个阶段:压密闭合阶段、爬坡剪胀阶段、锯齿剪断阶段、挤压碾碎阶段;锯齿结构面剪切强度-法向应力曲线近似呈三段线的特征,建立了三线段剪切强度准则;锯齿结构面剪切刚度-法向应力曲线呈上凸型特征,提出了结构面剪切刚度模型公式;锯齿结构面法向位移-剪切位移曲线呈先剪缩后剪胀的变化特征,提出了评价剪胀特性的经验公式。
This study is aimed to investigate the regularities of the shear strength, shear deformation and other mechanical properties of joint rock mass with different roughnesses under compression-shear stress. Marble specimens were prepared with the dentate height of 0, 1 and 3 mm, respectively. Then direct shear tests were conducted on the marble specimens under different normal stresses.Experiment results show that curves of shear stress and displacement can be divided into two types: sliding failure type and peak shear type. The climbing-gnawing process of joints goes through four stages: the compaction stage, the climbing stage, the saw-tooth cutting stage and the completely crushing stage. The curves of shear strength with the normal stress of the dentate joint present more obviously three-segment line feature, and a trilinear shear strength criterion is established. The curves of shear stiffness with normal stress present a convex type, and a shear stiffness model is put forward. The dilatancy curves of dentate joint present firstly shear contraction and then shear dilation, and an empirical formula for evaluating shear dilation is proposed.
作者
周辉
程广坦
朱勇
陈珺
卢景景
崔国建
杨聘卿
ZHOU Hui;CHENG Guang-tan;ZHU Yong;CHEN Jun;LU Jing-jing;CUI Guo-jian;YANG Pin-qing(State Key Laboratory of Geomechanics and Geotechnical Engineering. Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubci 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Water Conservancy and Civil Engineering,Shandong Agricultural University,Tai'an,Shandong 271018,China;China Coal Technology Engineering Group Chongqing Research Institute,Chongqing 400039,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第3期852-860,共9页
Rock and Soil Mechanics
基金
国家自然科学基金项目(No.51427803
No.51709257)
国家重点基础研究发展计划(973)项目(No.2014CB046902)~~
关键词
锯齿结构面
直剪试验
强度特性
剪胀特征
剪切刚度
dentate joints
direct shear test
strength characteristics
dilatancy characteristics
shear stiffness