Study on Damage Characteristics and Evolution Law of Macro‐Meso Structure of Surrounding Rock Under Mining Stress

ABSTRACT The control of surrounding rocks in dynamic pressure roadways has consistently been one of the challenging predicaments in the realm of underground engineering. Grounded on the engineering circumstances of Xinxin Coal Mine, this paper examines the evolutionary law of the stress field of the surrounding rocks in mining roadways. Through laboratory experiments, the stress state and evolutionary trajectory of the roof, along with the inner gang and outer gang rock masses under mining operations are reversed. The macroscopic failure, microstructure damage characteristics, and evolutionary law of the rock masses in diverse sections of the roadway under the influence of mining are acquired, and the asymmetric failure mechanism of the surrounding rocks of the mining roadway is disclosed. It is discerned that when the lateral pressure coefficient of the roadway exceeds 1, the impact of working face mining on the rock masses in different parts of the roadway is conspicuously distinct. The mining of the working face will perpetually deteriorate the stress environment of the surrounding rocks on the inner side of the roadway, and the surrounding rocks on the inner side will form a stress concentration zone, yet the influence on the stress of the surrounding rocks on the outer side is highly limited. Under the action of excavation unloading, the surrounding rocks undergo a certain extent of damage and disruption. With the escalation of mining influence, the damage to the surrounding rocks on the inner side of the roadway is acute, and the damage to the rock mass continues to intensify, but the damage and disruption to the surrounding rocks on the outer side are extremely limited.