(1. State Key Laboratory of Coal Resources and Safe Mining，China University of Mining and Technology，Beijing 100083，China；2. School of Mechanics，Architecture and Civil Engineering，China University of Mining and Technology，Beijing 100083，China；3. Tiefa Coal Industry Group Co.，Ltd.，Diaobingshan，Liaoning 112700，China)
Abstract：By using the method of strengthening broken rock and increasing supporting resistance，the mechanical properties，deformation and failure characteristics of surrounding rocks in Xiaokang coal mine are analyzed. Meanwhile，the instability mechanism of soft rock mining roadway is obtained and it is pointed out that the main reasons of supporting failure are inconsistent deformation，low supporting resistance and failure to utilize the supporting capability of the surrounding rocks. Taking the S2N8 haulage roadway of Xiaokang coal mine for example，the complementarity of the high strength bolt，high pretension cable，metal mesh and U-shaped contractible frame in the process of reinforcing surrounding rock is studied. Based on these studies，the complementary supporting technology of high strength and pretension bolt-mesh-cable supporting together with U-shaped contractible frame is introduced. In addition，in-situ industrial test has also been implemented；and the results show that the complementary supporting system can successfully avoid the multi-rebuilding in extremely soft rock mining roadway and the supporting once for all in Xiaokang coal mine can be adopted.
