基于Plesha本构的岩石节理多层结构模型研究

在Dong等工作的基础上1]，研究了基于Plesha本构的岩石节理多层结构模型。模型将节理面分解为不同层次细观结构面，每层结构面代表一级粗糙度，力学响应发生在最底层（基本面），上层结构面受力性状由其下层结构面平均化得到，依次进行得到节理宏观力学性状。节理破坏由下而上分层次进行，基本面破坏后，其上层结构面转化为基本面，基本面采用Plesha节理模型。模型能模拟弹性变形、滑动变形、磨损、剪断、压碎、分离等作用机理。定义的接触因子与绕流因子能考虑节理接触面积及粗糙度变化对渗流的影响。通过将粗糙度定义为等效起伏角，可以模拟节理循环剪切性状。采用ABAQUS的用户子程序UEL进行了模型验证与参数分析。

A hierarchical model of rock joints based on Plesha’s constitutive model

An improved hierarchical model of rock joints was proposed based on the work of Dong et al. (Dong J J, Pan Y W. A hierarchical model of rough rock joints based on micromechanicsJ]. International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts, 1996, 33(2): 111-123). According to this model, joint macro-asperity is decomposed into multi-level micro-asperity; joint behavior is decided by the performance of the lowest level asperity(also basic surface) through homogenization. Joints fail progressively from the lower level to higher level asperity, after the basic surface break down, the second lowest level asperity converts to the basic surface. The roughness of joint is represented by equivalent asperity angle. The model also include the effect of variation of contact area and roughness on the permeability of joints. The model can simulate the mechanism of elastic deformation, sliding, damage, shear-off, crush and separation of joints. Model verification and parameters sensitivity analysis were carried out by UEL of commercial soft package ABAQUS.