Real-time detection and information-based construction of roadways passing through faults: a case study

Abstract

During the period of working face passing through fault, the ground pressure behavior law of roadway in fault zone is complex, and study on roadway instability characteristics induced by fault-slip is a major concern for safety mining in underground coal mines. To investigate the distribution characteristics of mining stress under the influence of faults, a physical test was carried out with two fault structures. The results suggest that the slip and dislocation of faults induced by coal mining could cause rock strata to be impacted and crushed, which has a significant impact on the law of mine pressure behavior. The real-time detection including roof separation, anchor cable and bolt load was also carried out to evaluate the rationality of supporting scheme. The results showed that the roof separation was rapidly expanded within 10 m ahead of the working face with abrupt characteristics, reaching its peak within 2–6 h. The influence range of faults on roof anchor cable was within 30 m, and the anchor cable force was less than 40 kN under the influence of mining. The influence range of fault on roof bolts was less than 15 m, and on rib bolts was about 10 m. Field monitoring showed that 90% of the roof bolts pre-tightening force was less than 15 kN, which lead to insufficient support effect of bolts. The stability of the roadway was effectively controlled by adjusting the inter-row spacing of bolts and cables and increasing pre-tightening force of bolts. The research findings provide a basis for the optimization of support scheme, and also provide a reference for the support design of roadways under similar conditions.