【作者】 周莲君；

【导师】 彭振斌；

【作者基本信息】 中南大学 ， 地质工程， 2009， 博士

【摘要】 自然界中具有层状构造的沉积岩占陆地面积的2/3,层状岩体因开挖的影响,往往容易发生滑坡、崩塌等地质病害,造成巨大经济损失。目前国内外学者对于层状岩体的物理力学性质指标、结构面的抗剪强度测定及层状岩体边坡稳定性等方面的数值研究有一定的发展。论文通过收集前人资料、理论分析、室内试验及数值仿真技术,对层状岩体的压缩特性、结构面的剪切特性、层状岩体边坡稳定性及边坡锚固等相关方面进行了相应的系统研究,为工程实践提供科学指导。引入描述横观各向同性体的数值计算方法,并对比理论分析结果与数值计算结果之间的差别,表明数值方法能够较好地描述层状岩体的破坏特征。层状岩体室内单轴压缩试验得到不同结构面倾角下岩样的应力应变曲线,曲线表明随着结构面倾角的增大,层状岩体的压缩强度呈先减小后增大的趋势。同时,通过层状岩体单轴和三轴压缩数值计算,探讨了压缩情况下,层状岩体的强度和变形特征、岩样的结构面效应、尺寸效应,以及加载速率的影响,结果表明不同倾角下,岩样的压缩强度均随岩样直径的增大而减小,随加载速率的增大而增大,在实际试验过程中,应根据模拟的工况不同采用不同的加载速率；随着围压的增大,岩石应力峰值附近的塑性变形也增大,试件达到峰值强度的变形量也不断增大,试件延性特征增强,试样的弹性模量不断线性增大。数值模拟得到的岩石压缩强度变化规律与室内试验的规律相同。在结构面的室内和数值试验中,分析了结构面力学变形特性和影响参数,其结果表明,试样剪切强度与正应力之间符合Mohr-Coulomb线性关系；结构面的峰值剪切强度随剪切速率的增加逐渐增大；数值计算得到的结果与室内试验得到的结果相同,验证了数值试验的可靠性。对于层状岩体边坡的稳定性采用了三维数值方法进行计算,探讨了边坡滑动面随强度参数的变化情况,其结果表明,不同结构面情况下,随着结构粘结力的增大,边坡滑动面逐渐从临坡面向坡内移动,滑动模式由浅层滑动转换为深层滑动；随着内摩擦角的增大,边坡的安全系数逐渐增大,滑动面从深部往浅部移动。为了进一步探讨层状岩体的锚杆支护方法,分析锚杆在层状岩体中的受力和变形特征,建立了锚杆力学特征模型,该模型既考虑了锚杆的轴向应力应变特征也考虑了锚杆在横向的应力应变特征；利用数值方法对岩质边坡锚固效应的情况进行数值模拟,从宏观的角度揭示出锚杆加固后,层状岩体边坡不同区域的位移响应以及锚杆的应力变化情况。更多还原

【Abstract】 Sedimentary rock mass accounts for about 2/3 areas of earth surface in the world. The disasters such as slippage, falling often happen caused by excavation in the stratified rock mass, which leads to large amount of economic loss; but recently, the systematic studies have been developed in some degree on the physical mechanical characteristic of stratified rock mass,shear strength of structural plane and the numerical calculation method for stratified rock slope stability.The compressive characteristic of stratified rock mass, shear characteristic of structural plane, slope stability analysis for stratified rock mass as well as the reinforcement by cables for the slope are studied by the method of theoretical analysis, laboratory test and the numerical simulation technique, which will give guidance for the real project.The numerical method for the transversely isotropic rocks is introduced to describe the stratified rock mass, the comparative analysis are done for the theoretical and numerical results, which show that, the introduced numerical calculation method can well describe the failure characteristic of stratified rock mass;Test for stratified rock mass are done, the curves of stress-strain relationship are obtained for stratified rock mass with different inclinations of structure plane; Analysis for the characteristic of these rock mass are done, which show that, with the increase of structure plane inclination angle, the compressive strength shows the trend of first decreases then increases; According to the numerical calculation for stratified rock mass with axial and tri-axial compressive situation. Analysis are done for strength and deformation characteristic of rock mass with uniaxial compression, structural plane effect, scale effect, and the effect of loading velocity. For different structure plane inclination, the compressive strength of rock mass decreases with the increase of rock sample diameter; the compressive strength increases with the increase of loading velocity; in the real tests, the loading velocity should be chosen according to simulation situation; with the increase of surrounding stress, the plastic deformation near peak magnitude of stress increases as well as the deformation to reach the peak magnitude of strength, and the plastic characteristic of samples increases, while elastic modulus of rock samples increases in the linear way; the outputs of numerical calculation and laboratory tests are almost the same;The laboratory and numerical tests are done to simulate the strength and deformation of structural plane with different shapes, the structural plane deformation and mechanical chanracteristic and their influential factors are analyzed, which show that, shear strength of rock samples are in the Mohr-Coulomb linear relationship with normal stress; the peak value of shear strength increases with the increase of shear loading velocity; the results from numerical calculation are the same with the from laboratory test, which validates the reliable of the numerical data;The three dimensional calculation models for stratified rock slope are founded to analyze the effect of structural plane cohesion and internal friction angle to the safety factor and slip plane, which are seldom studied in recent. The analysis results show that, for the slip plane, when cohesion increases, slip plane moves from the place near slope surface to the internal of slope; while the increasing of internal friction angle leads to the slip plane moving from internal slope to the shallow slope mass;In order the futher study the cable reinforcement method in the stratified rock mass, the mechanical characteristic model for bolt is founded by theoretical method, the numerical model for the bolt not only considers the stress-strain characteristic in the axial direction but also in the transverse direction; then the bolting effect to the rock mass is simulated by numerical method; the displacement responses of slope and stress variation of bolting are analyzed in the macroscopic way.更多还原