Analysis of the influence of grouting on stress field of coal and rock mass with rough crack

Abstract

In order to study the distribution law of the stress field in the rough fractures hiding in coal and rock mass during the grouting process, the two-dimensional rough fracture profile is generated according to the random midpoint displacement method, and a fluid-solid coupled numerical model of grouting process was established by the COMSOL software. The stress field in the fractured coal and rock mass during the process is simulated, and the influence of the roughness and the grouting rate on the stress field of the mass is analyzed. The results show that the distribution form of the stress field during the grouting process mainly depends on the fracture roughness, and the stress is larger in the sunken region than the location of protrusion. With the increase of roughness, the distribution of the stress field is more complex and the stress concentration is more obvious in the coal and rock mass. At the same time, the grouting rate also affects the stress field. The grouting velocity has a linear relationship with the stress of the mass, and the impact of grouting velocity is more obvious. With the increase of roughness, the maximum stress of coal and rock mass is gradually reduced by the influence of grouting velocity.

Keywords

• grouting
• coal and rock mass
• rough fracture
• grouting velocity
• stress field
• gas drainage
• hole sealing