Damage Mechanism of Prefabricated Fracture-Grouted Rock Specimens under the Action of Dry and Wet Cycles

Abstract

In order to study the damage mechanism of fissure-grouted rocks in abandoned mine pumped storage, uniaxial compression tests were conducted using fissure-grouted rock specimens after dry and wet cycles. Additionally, acoustic emission sensors were used to track the damage of the rock specimens. The results demonstrate a negative correlation between peak strength and elastic modulus and a linear decrease in wave velocity and the mechanical characteristics of the fracture-grouted rock specimens with increasing dry and wet cycles. As the number of dry and wet cycles increased, the deterioration of the fracture-grouted specimens significantly decreased, and the internal microstructural adjustment of the specimens gradually leveled off. A rock constitutive model considering deterioration due to the dry–wet cycle is introduced, and the stress–strain curves under different dry and wet cycles are fitted. The model, which also accurately shows the mechanism of damage to prefabricated fissure-grouted rock specimens after dry and wet cycles, better characterizes the damage development law of prefabricated fissure-grouted rock specimens under the influence of dry and wet cycles.