摘要
结构面是影响岩体弹性模量的主要因素。基于岩体结构面参数统计,结合岩体应变能推导出的节理岩体本构关系,能够真实地反映岩体弹性模量的弱化和各向异性。在此基础上,以吉图珲铁路隧道围岩为例,研究了岩体弹性模量特征及影响因素。结果表明,该岩体弹性模量的弱化和各向异性程度随应力轴线与结构面法线的夹角而变化,并在夹角值为54.5°时达到最大;同时,岩体弹性模量的弱化与结构面内摩擦角和黏聚力成反相关,与结构面平均半径和密度呈正相关。当结构面半径超过3 m时,岩体弹性模量弱化趋于稳定。应力环境对弹性模量同样有影响,围压的增大,可使岩体弹性模量增大,同时减小了其各向异性和弱化的程度。当围压达到2.32 MPa时,各向异性及弱化现象消失。
Joint is the main factor influencing elastic modulus of rock mass. According to the statistics of joints parameters, a constitutive relation of jointed rock mass is deduced by combining with strain energy, which can reflect the weakening and anisotropy of elastic modulus. Then, the characteristics and influencing factors of elastic modulus of jointed rock mass are analyzed by using tunnel surrounding rock of Ji-Tu-Hui railway as an example. The results show that the weakening and anisotropy degree of elastic modulus vary with the angle between stress and structural plane normal, which can obtain the maximum value at the angle of 54.5°. Meanwhile, the weakening degree of elastic modulus is in negative correlation with the friction angle and cohesion of joints, but in positive correlation with the mean radius and density of joints. And when the mean radius is over 3 m, the elastic modulus tends to be stable. Confining pressure also has influences on the elastic modulus of rock mass. When confining pressure is increased, the value of elastic modulus increases, and weakening and anisotropy degree is decreased. When the confining pressure reaches 2.32 MPa, the weakening and anisotropy will disappear.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2016年第9期2505-2512,2520,共9页
Rock and Soil Mechanics
基金
国家自然科学基金重点项目(No.41030749)
"十二五"国家科研支撑计划项目(No.2012BAK10B06-02)~~
关键词
本构关系
岩体弹性模量
弱化
各向异性
影响因素
constitutive relation
elastic modulus of rock mass
weakening
anisotropy
influencing factors
作者简介
包含，1988年生，博士，主要从事岩体工程地质问题方面的研究工作。E-maihbaohangeo@163．com
通讯作者：伍法权，男，1955年生，博士，研究员，主要从事工程地质与岩体力学方面的研究工作。E-mail：wufaquan@mail．iggcas．ac．cn
