层状岩体受压力学特征结构面效应数值分析

Numerical Simulation of Structure Plane Effect for Mechanical Chaiacteristics of Layered Rock Mass Subjected to Compression

煤层底板岩体是沉积岩，具有显著的层状结构特点。为研究层状岩体压缩强度的结构面效应，通过FLAC3D数值软件，结合改进的遍布节理本构模型，建立层状岩体压缩数值模型，分析单轴、三轴压缩情况下的应力应变响应以及强度特征。研究结果表明：层状岩体压缩强度具有显著的结构面倾角效应。随着倾角的增大，层状岩体的压缩强度呈现先减小后增大的趋势。当结构面倾角为40＆#176;～80＆#176;时，岩体强度整体较低，破裂面主要沿结构面展开。数值试验和理论分析反映的岩体强度随结构面倾角变化规律一致。层状岩体弹性模量沿平行于结构面方向最大，而垂直于结构面方向最小，并随结构面与水平面之间夹角的增加而增大。

Coal seam floor rock mass is sedimentary rock and has obvious characteristics of layered structure .In order to study the structural plane effect on compressive strength of layered rock mass , the stress-strain response and strength characteristic of layered rock mass under uniaxial compression and triaxial compression were ana -lyzed by numerical simulation with FLAC 3D .The results showed that compressive strength of layered rock mass has remarkable effect of layer plane dip .The compressive strength of rock mass first decreases and then increases with the increase of structure plane dip angle .When the structure plane dip angle is 40 ＆#176;~80 ＆#176;, the strength of rock mass is low and the fracture plane develops in the structure plane .Numerical experiments and theoretical a-nalysis gave the consistent regularity of rock strength with structural plane dip variation .The maximum elastic modulus of layered rock mass is parallel to structural plane and the minimum in the direction perpendicular to the structural plane , and increases with the angle rise between the structural plane and the horizontal plane .