Bolt Supporting Parameters Optimization for a Roadway With Extra-thick Coal Seam

Taking a return airway T₁ in a coal mine as an example,firstly,the physic-mechanical characteristics of the coal and strata rocks in roadway roof are obtained by using field investigation and testing in the lab,secondly, the corresponding deformation and abutment pressure distribution characteristics of the return airway T₁ are then analyzed respectively combined with the field measurement of the deformation,roof separation and stress.By building the calculation model of the mining-induced T₁,the safety supporting with former controlling scheme is simulated and analyzed.Combining with the testing results of the coal and strata rocks in this roadway roof,pre-stress distribution characteristics of the roof coal strata,the supporting safety simulation of the former controlling scheme and field measuring results,the new bolt supporting parameters are finally determined.The final design is tested,which has achieved good effect.