Study On The Influence Of Cable Length On The Support Effect Of Mining Roadway

To explore the free segment length and anchorage length of prestressed anchor cable and law of influence in the roadway, and by use of the results of the study to optimized supporting, this paper adopts different means to systematically analyzed and studied of the free segment length and anchorage length of prestressed anchor in the roadway influence law.The main points are as following:(1)Using elasticity theory of semi-infinite space and the superposition principle of elasticity, solution of stress, strain and displacement of rock was derived under the effect of prestressed anchor, that provide theoretical basis for analysis the influence law of surrounding rock changes on free segment length of prestressed anchor cable.(2) Anchorage length and free segment length of prestressed anchor was numerical simulation analysis using the finite element analysis software FLAC3D.The obtained results and theoretical analysis results reciprocally verified, and summarizes the influence law of anchor cable and surrounding rock under the effect of anchorage length of prestressed anchor.(3)Under the geological conditions and supporting the status quo of Baiji 3412 workspace's gateroad bunker, combined with the numerical simulation method to analysis the influence law of anchor cable and surrounding rock under the effect of anchorage length and free segment length of prestressed anchor in roadway, and determined the optimal free segment length and optimal anchorage length of prestressed anchor in the condition.(4) Analyzing and comparing two anchor length on the influence of the surrounding rock steady by field measurement data. The correctness of optimal anchor length from above analysis was verified.(5)The similarities were found by comparing the influence law of anchor cable and surrounding rock under the effect of anchorage length and free segment length of anchor in roadway and the influence law of stress demarcation point of cable bolt.Research results of this paper can provide instruction meaning and reference value for design of anchor supporting parameters.