损伤盐岩短期自恢复特性试验研究
Experimental research on properties of short-term self recovery of damaged salt rock
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摘要: 为了解盐岩在产生损伤以后的力学性质以及在恒温环境下的短期自恢复特性,设计了盐岩剪切损伤后的自恢复试验,研究了损伤盐岩相关力学参数随恢复时间的变化规律。试验结果表明,自恢复对盐岩内摩擦角的恢复作用明显,而对黏聚力的恢复不明显;在恢复的初期,损伤盐岩抗剪强度随之降低,继续恢复则会出现相对增强,最终会进入长期恢复阶段,趋于稳定;经一定时间的恢复以后,损伤盐岩的抗变形能力有所增强的同时,其变形能力也有所增强;对盐岩损伤自恢复的研究可以分为长期和短期,试验中两者的分界点为7 d左右。通过对盐岩损伤自愈合的理论进行讨论分析,可以知道盐岩的自恢复并不是简单的力学性质的增强,更体现在综合性质的改善,同时伴随部分力学性质的劣化;通过对损伤变量的拟合,可以看出试件的损伤值在自愈合过程中的发展变化规律。Abstract: In order to understand the mechanical properties and short-term self recovery features of salt rock with damage under constant temperature, the self recovery tests on the salt rock with shear damage are designed, and the variation laws of related mechanical parameters with the time for recovery are studied. The test results show that the recovery of internal friction angle is obvious, and that of cohesive force is not obvious. In the early recovery stage, the shear strength decreases and then relatively increases with the to recovery, and eventually enters into the long-term recovery phase. After recovery, with the increasing ability of resistance to deformation, the deformation ability of damaged salt rock also increases. The researches on the self recovery of salt rock with damage should be divided into long-term and short-term ones, and the dividing point is about 7 d. Through the discussion and analysis of the self-healing theory, it is known that the recovery is the strengthening of mechanical properties and improvement of comprehensive quality, sometimes along with degradation of some mechanical properties. By fitting the damage variables, the variation of damage values of damaged specimens in the process of self healing is released.