Support parameters optimization and engineering application of roadway with broken-expand surrounding rock in deep

Aiming at the deformation characteristics and the support problem of deep high stress broken-expand surrounding rock, the secondary support of the deep roadway engineering of Fenglong coal mine in Jiangxi Province, China, is carried out to optimize the parameters. First of all, according to the characteristics of deep roadway deformation in Fenglong coal mine, the specific support scheme was put forward on the basis of the original support, then, the secondary support parameters and the support time are designed. The softening strength parameters of the surrounding rock in the roadway are obtained by using the piecewise linear strain softening model and the dilatancy angle of the rock mass. Considering the strength effect of cable anchor, the calculation equation and support strength index ID concept of anchor cable are put forward, and the corrected calculation parameters of anchorage effect are given. Then, the numerical calculation is carried out for 16 schemes, meanwhile, the optimal scheme of the comprehensive evaluation index Es of roadway engineering stability is adopted. The influence of different anchoring effect on the stability of roadway and different secondary displacement value on the stability of roadway are analyzed respectively. Finally, the optimized support scheme is used to carry out the engineering practice, the results of monitoring the deformation of roadway by cross method show that the deformation value is within the controllable range, which can better control the roadway deformation.