基于RFPA2D复合局部挠曲岩体数值模拟

为研究复合局部挠曲岩体强度特征以及破坏规律，采用岩石真实破裂软件RFPA^2D，对水平层面挠曲30°，45°，60°，75°的复合岩体进行单轴压缩试验模拟。模拟结果表明:挠曲角为30°，45°，60°，75°的复合岩体破坏面几乎与挠曲段夹层重合，其挠曲端部均产生了垂直于挠曲段夹层的裂纹；复合单斜岩体与复合挠曲岩体破坏面的形成因素大致相同，夹层强度是2种岩体失稳的主要因素；复合挠曲岩体单轴抗压强度随挠曲角增大同样呈“U”型变化，与单斜岩体变化趋势一致；当水平层状岩体发生挠曲后，其单轴抗压强度减小，当挠曲角为60°时，强度降低25.19%，当挠曲角为75°时，强度降低0.17%。；随着均质系数m的增大，复合挠曲岩体单轴抗压强度以及轴向应变均出现逐渐递增的趋势，且不同m值，其岩体裂隙扩展方式具有明显差别。

Numerical simulation of composite local flexural rock mass based on RFPA2D

In order to study the strength characteristics and failure laws of the composite local flexural rock mass,the rock real fracture software RFPA^2D was used to carry out the uniaxial compression test simulation on the composite rock mass with the horizontal bedding deflecting 30°,45°,60° and 75°,respectively.The simulation results showed that the failure surface of the composite rock mass with the deflection angle of 30°,45°,60° and 75° almost coincided with the flexural section interlayer,and the cracks being perpendicular to the inclined interlayer occurred at the end of flexure.The formation factors of failure surface on the composite monoclinic rock mass and the composite flexural rock mass were roughly the same,and the interlayer strength was the main factor causing the instability of two types of rock mass.The uniaxial compressive strength of composite flexural rock mass also changed in a “U” shape with the increase of deflection angle,which was the same as the monocline rock mass.After the horizontal stratified rock mass occurred the flexure,the uniaxial compressive strength strength decreased,when the deflection angle was 60°,reaching 25.19%,when the deflection angle was 75°,decreasing only 0.17%.With the increase of homogeneity coefficient m,both the uniaxial compressive strength and axial strain of composite flexural rock mass increased gradually,and the modes of rock fracture expansion had obvious difference when the m value changed.