应力损伤盐岩的声波、溶解试验研究

Experimental research on acoustic and dissolved properties of stress damaged salt rock

采用声波技术研究盐岩在单轴载荷条件下的损伤特征,并对受损盐岩进行溶解试验分析,以此来分析盐穴建造期盐岩的损伤溶蚀机制。试验发现:随着轴向应力的增加,侧向波速逐渐较小,在达到极限强度后波速快速减小,而不像轴向波速那样在弹性压密阶段会出现小幅增加之后才开始减小;盐岩所受压力越大,对应的溶解速度越快。由岩石单轴强度理论和损伤理论分析表明,盐岩应力损伤由盐岩晶粒相互错动促使微裂纹增多所致,侧向波速确定的损伤变量与应力具有相关性,盐岩的溶解速率随损伤变量的增加而增加。

In this paper, acoustic wave technology was used to study the damaged characteristics of salt rock under uniaxial loading and the effect of damage on dissolution to reveal the parietal injury dissolved characteristics in salt cavity construction period. The study shows that： when the stress increases, the lateral velocity, unlike axial velocity gradually decreasing, decreases rapidly when reaching the ultimate strength. The greater is the pressure on rock salt, the faster is the salt rock dissolving. Based on the analysis of rock strength theory and damage theory, we conclude that the stress damage of salt rock is caused by the increase of micro-cracks resulting from crystal dislocation with each other. The damage variable and stress are closely related. The rock salt dissolution rate increases with the damage variable growing.