非贯通裂隙岩体单轴压缩破坏的数值模拟研究

Numerical simulation of uniaxial compressive failure of prefabricated fractured rock sample

为了研究非贯通裂隙岩体在单轴压缩荷载作用下的损伤破坏情况,采用二维的真实破裂过程分析软件RFPA2D进行了相应的数值模拟研究。数值模拟结果表明:(1)由于RFPA2D软件考虑了岩石材料的非均匀性,所以模拟出的宏观单轴抗压强度小于细观单元平均单轴抗压强度;(2)在弹性加载阶段,最大剪应力的最大值出现在预制的两条裂隙的尖端,随着轴向应力的不断增大,最大剪应力的最大值也随之不断增大,待加载到峰值附近,宏观裂隙形成;(3)破坏过程声发射模拟结果,有效地反映了预制非贯通裂隙岩样在受到单轴压缩荷载时,内部累积损伤、形核、宏观裂纹出现直至断裂失稳的过程。

In order to study uniaxial compressive failure of prefabricated fractured rock sample,a software named real failure process analysis-RFPA2D is employed to conduct some numerical simulation.The results show that:(1) the macroscopic uniaxial compressive strength simulated by RFPA2D software is smaller than the average uniaxial compressive strength of the meso-elements because the heterogeneity of rock materials is considered.(2) in the elastic loading stage,the maximum value of the maximum shear stress appears at the tips of the prefabricated two cracks.With the increasing of the axial stress,the maximum value of the maximum shear stress also increases.When the stress is near the peak value,macroscopic cracks are formed.(3) the simulation results of acoustic emission effectively reflect the process of internal cumulative damage,nucleation,macroscopic crack occurrence and instability when the prefabricated fractured rock sample is subjected to uniaxial compression.