热力耦合路径下花岗岩细观破裂特征及数值分析

岩体热力耦合下破坏机制及响应特征是防治与治理灾害发生的理论基础,也是高放射性核废料深地层处置关注的重要问题。细观尺度下,基于北山花岗岩单轴拉伸实验,考虑3种不同耦合路径,对比分析试样破坏区域SEM图像,揭示细观破坏特征。并利用数值仿真,建立细观模型,分析了热开裂特征及能量变化规律。进而指出裂纹拓展数量与角度关系,同时分析了微裂纹空隙率与应力、角度关系。主要结果表明:不同耦合路径下裂纹扩展细观特征迥异,演化顺序迥异,耦合路径与非均质性对裂纹细观特征变化均有影响。

Paths on thermal-mechanical coupling failure of meso-scale granite under uni-axial tension and numerical analysis

The failure mechanism under thermal and mechanical coupling is a key issue for high-level radioactive waste disposal in deep geological rock，and is also the basis for disaster prevention.Based on the uni-axial tension test of granite taken from Beishan region，the authors used three different coupled loading paths to analyze the failure mode of SEM pictures and reveal the characteristics of meso-scale failure.Meanwhile，the law of thermally induced cracking propagation and strain energy is obtained from the simulation of meso-scale sample considering the various materials and distribution.Furthermore the authors establish the relationship between the angle and number of crack，and explain actual porosity evolution with loading stress and different crack angles.The results show that both coupled paths and heterogeneity lead to failure.There is a clear distinction of cracking mechanism between increasing temperature under constant tension.