基于RFPA2D岩石渗流剪切破坏过程研究

Research on the shear failure process of stone seepage based on RFPA^(2D)

为探究岩石渗流剪切破坏规律,以砂岩为例,利用RFPA^(2D)软件进行数值模拟。结果显示:砂岩在渗流剪切破坏过程中分为稳定变形、亚稳定变形、失稳前兆和失稳破坏等4个阶段;伴随着加载过程,模型中心区域应力发生偏转升高,随之因应力集中而产生少量微裂纹,且拉伸性微裂纹出现时间先于剪切性微裂纹,两者汇合贯通后形成宏观破裂面;声发射活动贯穿整个渗流剪切破坏过程,表现为峰值剪应力前,声发射特征参数指标较低,之后,声发射特征参数指标骤增,通过裂纹扩展图与声发射图对比阐释了砂岩渗流剪切破坏过程中的裂纹扩展规律。研究岩石在剪切荷载和降雨渗流耦合作用下的破坏过程具有重要的工程应用和实践意义,利用RFPA^(2D)软件进行模拟可为受降雨影响的岩质边坡稳定性研究提供新思路。

To explore the laws of rock seepage and shear failure,sandstone was taken as an example,RFPA^(2D) software was used to carry out numerical simulation.The results show that the sandstone is divided into four stages in the process of seepage and shear failure:stable deformation,meta-stable deformation,instability precursor,and instability failure;along with the loading process,the stress in the center of the model deviates and rises,followed by stress concentration.However,a small amount of microcracks are generated,and the tensile microcracks appear earlier than the shearing microcracks.After the two merge and penetrate,a macroscopic fracture surface is formed;the acoustic emission activity runs through the entire seepage shear failure process,which appears before the peak shear stress.Acoustic emission characteristic parameter index is low,afterwards,the acoustic emission characteristic parameter index increases sharply.The comparison of the crack propagation diagram and the acoustic emission diagram illustrates the crack propagation law in the process of sandstone seepage and shear failure.Studying the failure process of rock under the coupling action of shear load and rainfall seepage has important engineering application and practical significance.The use of RFPA^(2D) software simulation can provide new ideas for the study of the stability of rock slopes affected by rainfall.