Study on deformation and failure mechanism and support technology of soft rock shaft bottom roadway

doi:10.13199/j.cnki.cst.2017.02.008

Abstract：In order to solve the problem,such as large deformation and failure of shaft bottom roadway,large area serious roof caving of loaded-car line,instability of horsehead after repeatedly repairing,by means of geological survey,laboratory test and numerical simulation,the soft rock roadway of Xing'an Coal Mine of the Mesozoic soft rock was divided into high caving zone,serious deformation zone and general deformation zone,the deformation and failure characteristics mainly of roof falling,shrinkage at two sides and roof caving were analyzed.The cause of its failure was summarized as follows:roadway was deep;geological structure was complex;original support was irrational.The progressive caving mechanism of layered roof from rock plate separation evolved into breaking was revealed.The double chamber stability coupling control countermeasure,which using the self-stability of caving arch and surrounding self-bearing the ability to form the upper chamber and using the flexible layer truss coupling support to form the lower chamber,was put forward.The reinforcement engineering practice showed that the bolt + mesh + anchor + truss supporting design scheme of Xing'an Coal Mine four level loaded-car line effectively controlled the deformation of surrounding rock of roadway,the final convergence of two roadway sides was 30 mm,the maximum floor heave was 27 mm,the deformation tended to be stable.