运用多功能试验机首次开展岩盐非连续疲劳试验，研究了时间间隔作用下的岩盐的力学特性（包括变形和弹性常数）的演化规律。试验结果显示：（1）与常规疲劳情况不同，间隔疲劳过程中时间间隔后的循环产生的轴向残余应变总大于时间间隔前的残余应变，且径向和体积残余应变呈现出与轴向相同的规律。（2）时间间隔后的循环内弹性模量总体大于时间间隔前的循环内弹性模量，但泊松比随时间间隔变化不明显，时间间隔前、后均呈相似的上升趋势。（3）间隔疲劳过程中的时间间隔对塑性变形的积累有加速效应，时间间隔越长，疲劳过程中残余应变积累越快，岩盐疲劳寿命越短。（4）循环过程中无应力静置时间间隔的出现，为岩盐内部结构的整体调整提供了时空条件，有利于晶粒在残余应力作用下归位并产生新的滑移面，后续加载时晶粒回到原应力峰值对应位置将耗散更少能量，宏观上表现为塑性变形的加速积累，岩盐更容易发生疲劳破坏，疲劳寿命降低。

Discontinuous cyclic loading/unloading fatigue tests were conducted on salt rock to investigate the evolution laws of mechanic characteristics (i.e., deformation and elastic constants) at different time intervals by using a multifunctional testing machine. The results show that compared with the residual deformation in the normal loading/unloading circle, residual deformation in circle after interval is greater than that in circle before interval. The behavior of the radial and volumetric residual deformation follows the same rule as that of axial deformation. Modulus of elasticity in circles after interval is larger than that in circles before interval generally, while Poisson’s ratio does not change obviously with interval which shows a similar upward trend before and after the time intervals. Interval accelerates the accumulation of residual deformation. The longer the interval is, the faster the residual deformation accumulates during fatigue process, and the shorter the fatigue life of salt rock. The interval without applied stress is beneficial to regression of crystal lattice under the function of residual stress and to generating new slip planes. Less energy consumption is caused when the crystal lattice returns to its initial position corresponding to previous peak stress value. Salt rock samples break more easily and have shorter fatigue life at the macro level.