浸水时间对饱水岩石损伤破坏过程中声发射特征影响的试验

Experimental study on AE properties during the damage process of water-saturated rock specimens based on time effect

为研究不同浸水时间饱水岩石损伤破坏过程中的力学特性和声发射特征,对天然及不同浸水时间的饱水闪长岩进行单轴压缩力学试验和声发射试验,研究单轴应力状态下其力学特性和声发射特征,结合累积声发射数与损伤变量一致的观点,建立了基于浸水时间的饱水岩石声发射损伤模型。结果表明:饱水岩石的单轴抗压强度和弹性模量随浸水时间的增加呈指数的变化规律逐渐减小,浸水60 d后其值均趋于稳定;在加载的各个阶段不同浸水时间的饱水岩样均有声发射事件产生,声发射事件率与岩样的应力-应变关系趋势均具有较好的一致性;声发射累积数的变化规律与岩样内部损伤演化规律具有一致性。

To study the mechanical properties and AE properties during the damage processes of different water-saturated rock specimens which have been dipped in water for different times, the experiment of uniaxial loading and AE of diorite with different water contents were conducted. By investigating the properties of mechanics and AE, the damage model with AE events based on the time effect of water-saturated rock specimens was established according to the accumulated AE events related with damage variable. The results show that the strength and elastic modulus of water-saturated rock specimens decline with the dipping time in water as the laws of negative exponent. The values of strength and modulus trend to constant after it has been dipped in water for more than 60 days. Furthermore, the AE events occur during each loading step for specimens dipped in water for different times and the AE rate variation is consistent with the stress-strain variation law. The accumulated AE events variation is consistent with damage evolution in the specimens. © 2015, China Coal Society. All right reserved.