Study on Deformation Failure Mechanism and Control Technology of Surrounding Rock in Soft Rock Roadway

In order to reveal the mechanism of surrounding rock deformation and instability of soft rock roadway in 12# working face of Puhe coal mine, and synthetical analysis of the surrounding rock, deformation and failure of the roadway shows that the original support scheme is difficult to maintain the stability of roadway. Thus the basic concept of roadway surrounding rock control: Single anchor bolt form a compression zone to control the failure and expansion of surrounding rock, and a comparable number of anchor bolts form a homogeneous compression zone to inhibit the development of surrounding rock plastic zone. The “anchor blot + anchor cable net + concrete shotcrete support plan (arrangement of anchor cables four to five)” is proposed. Furthermore, and FLAC3d numerical simulation software was used to verify the rationality and reliability of the supporting scheme of “bolt + anchor cable net + concrete shotcrete support scheme (four to five anchor cables)” support scheme. The on-site monitoring results show that the soft rock roadway in Puhe Coal Mine 12# working face return airway passes through the “bolt + anchor cable net + concrete shotcrete support scheme (anchor cable four to five arrangement)” to reduce the surrounding rock deformation and become stable. The sinking amount of the roof and floor in the roadway is 251.2 mm, the convergence amount of the two sides in the roadway is 231 mm, supporting system and surrounding rock form the stable compression zone, the soft rock roadway can be effectively controlled by the support scheme, which can provide reference value for other similar engineering.