危岩体断裂特性的网格重构数值仿真研究

危岩体稳定是三峡库区的主要关注点之一.为探究不同裂纹赋存形态以及不同降雨工况下危岩体断裂的变形特性,基于围道积分原理,在Abaqus平台上利用Python语言开发了基于断裂力学理论的危岩体任意裂纹扩展的网格重构数值模拟方法,该方法与以往危岩体裂纹扩展数值模拟方法相比,能够体现危岩体裂纹尖端的断裂力学特征,实现连续介质中...

Numerical Simulation Study on Grid Reconstruction for Fracture Characteristics of Dangerous Rock Mass

The stability of dangerous rock mass is one of the main concerns in the Three Gorges Reservoir Area.In order to explore the fracture shape characteristics of dangerous rock mass under different crack occurrence and different rainfall conditions,this paper develops a new numerical simulation method for crack propagation based on the principle of circumference integral and the fracture force method has been developed on Abaqus platform with Python language.Compared with the previous numerical simulation methods of crack propagation,this method can reflect the fracture mechanics characteristics of the crack tip,and the mesh reconstruction method can realize the discontinuous expression in continuous media.Based on this,the paper carries out numerical simulation of W15 dangerous rock mass in Taibai,Chongqing.The results show that the new method of grid reconstruction based on the fracture force method has good adaptability and it provides a new numerical simulation method for fracture deformation cha-racteristics simulation of dangerous rock mass,and with the increase of fracture angle,the normal stress value and shear stress value of dangerous rock body first increase and then decrease,and the horizontal displacement value decreases continuously with the increase of fracture angle.With the increase of fracture angle,the effect of fracture on the deformation of dangerous rock mass decreases gradually,and the horizontal displacement mainly focuses on the protruding part of dangerous rock mass.The increase of fracture length has the greatest influence on the stress and deformation of dangerous rock mass,which makes the deformation concentrate from the protruding part of the dangerous rock mass to the fracture.The deformation and displacement of dangerous rock under heavy rain are larger than that under natural conditions,which is one of the most important factors affecting the stability of dangerous rock mass.The cracks of dangerous rock mass propagate towards the protruding part,which is mainly dominated by mode I propagation.With the continuous crack propagation of cracks,modeⅠstress intensity factor increases exponentially,while modeⅡstress intensity factor changes little.The longer the initial crack length,the greater the absolute value of modeⅠstress intensity factor and modeⅡstress intensity factor.