Analysis of Fracture Modes and Acoustic Emission Characteristics of Low-Frequency Disturbed Water-Bearing Soft Rock With Different Cyclic Initial Value

In the complex geological environment of deep mining area, water-bearing soft rock is more prone to damage and destruction by low-frequency disturbance. In this paper, the dynamic–static combination test was conducted on the basis of uniaxial compression test by using creep dynamic disturbance impact loading system and acoustic emission technique. The test results show that with the increase of the initial value of disturbance loading, the fracture morphology of sandstone gradually changes from a single major crack to multiple cracks coexisting, and some saturated sandstones lose the bearing capacity in the process of disturbance, presenting a cone-shaped fracture surface. The increase of the initial value of the disturbance changes the bearing capacity of the sandstone, and the peak energy of acoustic emission reaches the maximum value when the initial value of the disturbance is 80% UCS. The results of the study can provide some reference for the stability analysis of deep water-rich soft rock mines.