Damage evolution characteristics of rock mass containing defects during loading were analyzed by u-sing RFPA2Dnumerical analysis software.Three circular defects with small strength and elastic modulus were preset in the model.The results show that the damages of defective rock mass during loading can be divided in-to four stages: zero damage at initial stage of loading,stable growth of the damage,rapid growth after the first crack appearance,and a large crack stage throughout the entire rock mass appearance.The stress concentrates around the defects during loading,which results in the proliferation and expansion of cracks.Preset defects e-ventually are communicate through big cracks and rock mass are destroyed.Meanwhile,the number of cracks is increased by segment after the first crack appearance and up to the peak near the peak point. During the process of crack proliferation and expansion,the acoustic emission characteristics are obvious.The results of the study have important values in guiding and analyzing the damage process of defective rock mass process.%为研究缺陷岩体具体的破坏过程,利用RFPA2D数值分析软件,在模型中预置3个强度和弹性模量均较小的圆形缺陷,模拟载荷作用下含缺陷岩体的损伤演化特征.结果表明:载荷作用下含缺陷岩体的损伤分为加载初期的零损伤、损伤稳定增长阶段、缺陷内出现第一条裂纹后的快速增长阶段、贯穿整个岩体的大裂纹出现阶段;随着加载的继续,缺陷周围开始出现应力集中,从而导致裂纹的增殖、扩展,预置缺陷最终通过大裂纹进行联通,造成岩体发生破坏;同时,从缺陷内出现第一条裂纹开始,裂纹数量呈现分段性增长,峰值点附近达到最多,且裂纹增殖、扩展等发生过程中,声发射特征明显.研究结果对分析缺陷岩体的破坏过程具有重要的指导意义.
展开▼
