不同温度条件下盐岩卤水浸泡后损伤自恢复特性

为了研究地下盐穴开挖扰动区（EDZ）损伤盐岩在盐穴综合利用过程中的自恢复特性，设计了损伤盐岩在卤水温度作用下的自恢复试验。结果表明：损伤盐岩经过卤水浸泡后在不同温度下烘干时力学性质可以得到恢复，在试验温度范围35～80 ℃内，其恢复效果随着温度的增加而增强。经过恢复处理的损伤盐岩试件二次加载时的声发射特征显示，其Felicity比低于0.1，Kaiser效应基本不成立，说明损伤盐岩在自恢复处理过程中其内部损伤在细观尺度上发生愈合。根据损伤盐岩试件自恢复处理后的细观形貌特征，总结出盐岩损伤恢复3种不同的细观机制：基于扩散作用的损伤微裂纹愈合，基于NaCl晶体重结晶作用的微裂隙充填以及破碎区NaCl晶体颗粒的愈合黏结。盐岩损伤恢复过程中，裂纹中充填的饱和卤水为裂纹中的物质传递提供了通道，同时提供了大量的结晶基础物质，为盐岩损伤愈合奠定了基础。温度的升高为盐岩损伤恢复提供了更高的能量，提升了损伤愈合速度，同时使氯化钠重结晶密度增加，从而提高了损伤恢复程度。

Damage self-healing property of salt rock after brine immersion under different temperatures

In order to understand the self-healing property of the damaged salt rock in excavation disturbed zone (EDZ) during the utilization of salt cavern, self-healing experiments of damaged salt rock under the effect of the brine soaking and drying were carried out. The results are as follows. The mechanical properties of the damaged salt rock can be recovered after being soaked in brine and dried at different temperatures. The recovery effect increases with the increase of temperature in the test temperature range 35-80℃. The acoustic emission characteristics of the damaged salt rock specimen during the secondary loading process after healing show that the Felicity ratio is less than 0.1. It can be concluded that the Kaiser effect is not established, which indicates that part of the damage of the salt rock can heal at the mesoscopic scale during the self-healing process. Based on the mesoscopic morphology characteristics of the salt rock specimens after healing, three different physical mechanisms of damage healing in rock salt are summarized: healing of microcracks based on diffusion, filling of microcracks based on crystallization of NaCl crystal, healing of the boundaries of crystal in the crushing zone. During the process of salt rock damage healing, the brine filled in the cracks not only provides a channel for the material transfer but also provides a number of base material for crystalline, which lays the foundation for damage healing. The increasing temperature provides more energy for the healing and increases the recrystallization density, improving the speed and the degree of damage healing.