地震条件下陡峭岩体崩塌式渐进破坏研究

Numerical Simulation of Steep Rock Collapse Progressive Dynamic Failure under Seismic Waves

基于离散单元法DEM,推导颗粒黏结-阻尼振动-运动演化方程,建立三维陡峭岩体模型,在地震横波与纵波条件下,进行岩体渐进式破坏演化动态过程模拟,在模型中实时跟踪9个监测点相关力学及运动参数,分析从稳定至滑动,再到碎石运动演化过程中参数变形情况。结果表明:细观颗粒间从黏结到损伤断裂再到运动的过程中,非线性运动特征差异化明显。水平向横波作用下,左侧岩体渐进式破坏严重,呈现出断裂-分离-接触碰撞-再分离的运动演化过程。不同振动强度下,岩体破损程度差异明显,振幅15以上岩体破坏严重。纵波单独作用下,岩体虽发生水平向裂纹,中部发生较大变形,但整体结构保持较好;模拟发现横波是岩体破坏的主要因素,纵波和横波叠加作用下两侧岩体破坏严重。

Based on the discrete element method DEM,this article constructs the constitutive model of particles connected damage.Three dimensional steep rock model is built to simulate the rock progressive failure evolution process.This paper selects nine test points and analyzes the parameter variation from stable state to slide,and then the evolution of gravel movement.The results show that the meso-particles from the adhesion to the fracture and then to the movement,nonlinear motion characteristics are differentiated obviously.Under horizontal earthquake,the left side of rock shows progressive destruction,that is fracture-separation-contact collision and then separate motion.Under different seismic intensities,there are obvious differences in rock damage.For 15.0or more seismic amplitude,the rock is severely damaged.Results show that if there is P-wave input only,the rock is cracked,the central portion suffers larger deformation,but the overall structure remains intact.Seismic shear wave is the main factor of rock damage.Under the superposition of the longitudinal waves and transverse waves on both sides,the damage is serious.