Research On Improving Support Pattern In Sublevel Roadway Of Jinchuan Third Mining District

Support problem in high-stress roadway is one of the more complex international problems in rock mechanics. For a long time,people working in mining, tunneling and rock mechanics have done lots of research on failure mechanism and supporting technique in high-stress roadway. But because of the complexity of geological condition of high-stress roadway, it is difficult to solve the problem.Due to the broken surrounding rock and outstanding tectonic stress in Jinchuan mining area, and in the process of construction and mining, serious deformation and destruction have occured in many roadways. The deformation of roadway can be controlled in some degree by the current shotcrete rock bolt mesh support of grouted bolt in mining area, but the support effect is not ideal. Many roadways have been repaired for many times, and the cost of roadway support is high. Over the years, the company has been seeking a new way of supporting, and hoped to solve the support problem of bad condition roadway in a degree.The author do series of research based on 1438 sub-level of Jinchuan third mine. First, it analysis the failure characteristics according to the spot investigation and relative information; Second,it analysis failure reason of high-stress roadway and the problem lying in supporting and puts forward the improved measures combining with the actual situation of the test section of roadway,gets the improved support scheme, and uses numerical simulation to compare the improved support scheme with the current support scheme; In the end, it evaluates the method based on the monitoring data of on-site support experiments.By researching the support test on 1438 sub-level of Jinchuan gets the following conclusion. Shear failure easily occurs beneath the wall of the roadway, and it should be strengthened to support. The length of bolt is short and the bolting force is insufficient which can’tprovide radial stress are the key factor of the bad effect of the current shotcrete rock bolt mesh support, at the same time, the metal mesh and shotcrete are flawed. When more pre-stressed bolts are assigned systermly, the cone compression zone of adiacent bolts will overlap each other and form serial supporting ring around the roadway. The support effect of improved prestressed-hollow bolt + TECCO mesh +shotcrete is better than the current shotcrete rock bolt mesh support of grouted bolt.