反倾层状岩质边坡变形破坏的颗粒流模拟研究

基于颗粒流程序对反倾层状岩质边坡变形破坏过程进行模拟,并考虑岩体结构面参数(岩层倾角、层厚及层理剪切强度)对其变形破坏机制的影响。数值模拟结果表明:边坡岩层的主要变形破坏方式为弯曲变形、折断破坏,变形首先发生在坡顶,而破坏是从坡脚开始,边坡的变形破坏过程具有明显的悬臂梁特征;岩层倾角对反倾岩质边坡整体性失稳破坏方式有较大影响,随着岩层倾角的增大,边坡后期整体性破坏方式由滑移型逐渐过渡为倾倒型破坏,坡体内部岩体出现变形及破裂损伤的深度也逐渐增加;随着岩层厚度增加,坡脚岩体抗折断能力增强,破坏方式由折断破坏向剪切破坏发展,边坡后期的整体性破坏方式也由滑移型向倾倒型过渡;岩层层面剪切强度是影响边坡变形的重要因素,层面剪切强度越小,边坡发生弯曲变形的程度越大。

Simulation of Deformation and Failure for Anti-dip Layered Rock Slope Using Particle Flow Code

Based on the two-dimension particle flow code software (PFC2D ), the deformation and failure process of anti-dip layered rock slope is simulated, and effects of rock mass discontinuity parameters (dip angle, thickness and joint shear strength) on its deformation and failure mechanism were taken into account. The numerical simulation results show that the main failure mode of the slope strata is bending deformation and fracture failure. The deformation first occurs at the top of the slope, while the failure starts from the slope foot, and the failure characteristic of this kind of slope is similar to that of cantilever. The rock dip angle has a great impact on the overall failure mode of the anti-dip rock slope. With the increase of the rock dip angle, the integral failure mode of the slope in the later stage gradually changes from sliding mode to toppling mode, and the depth of rock deformation and fracture damage inside the slope body increases gradually. As the thickness of the rock layer increases, the Fracture resistance of the rock mass at the foot of the slope increases, the failure mode develops from fracture failure to shear failure, and the integral failure mode in the later stage of the slope also transitions from sliding mode to toppling mode. The shear strength of joint is also an important factor influencing the slope deformation. The smaller the shear strength at the stratum level, the greater the bending deformation of the slope.