Research on the roadway control technology of bolt key support in high stressed soft rock

Aiming at the problems that the deformation of surrounding rock support body were serious in high stressed soft rock, the optimal support time and support strength were analyzed and quantified by using roadway convergence monitoring and broken rock circle measure which were based on the Fenner formula and the Mohr strength theory.Built on the bolt core support mechanism and nonlinear design method of coupling support, the transformation process of three kinds of roadway deformation mechanics mechanism was studied.Three active support schemes were proposed.They were “new type of bolt adhesive+bolting with wire mesh and steel trip” flexible truss coupling support, “a new type of high-pressure grouting bolt and its reinforcement roadway method” and “anchor net spray” support program.A new type of R & D anchor adhesive had the advantages of early solidification time and high early strength, and can quickly bond the bolt and the surrounding rock.A new type of high-pressure grouting bolt and its reinforcement roadway method formed a multi-level combination of arch coupling support to improve the contact with rock mass self-bearing capacity, while expanding the supporting structure of the effective carrying range.The practice showed that the bolt support functions were played a key role in support programs and the serious deformation of the roadway was effectively controlled.Support costs were reduced.The stability of the roadway was guaranteed.