Study On Deformation And Support Of Roadway In Soft Rock At Depth In Jinchuan No.2 Mining Area

Roadway support under deepness and high stress condition is a most complex international problem in rock mechanics. For a long time, people working in mining, tunneling and rock mechanics do lots of research on failure mechanism and supporting technique of deep high stress roadway .But because of the complexity of deep tunnel geological condition, it is difficult to solve the problem.With the increasing of mining depth, the stress of surrounding rock in second mine block in the Jinchuan mine is also increasing. Especially in recent years, the problem of roadway's support becomes more and more serious. The traditional ways of bolt and U-formed arched falsework have been destroyed badly in the roadways under the 1000m level. It is the first time that the roadway deformation's rate is so quick and the deformation is so large. Some places have started repairing tunnel before using. How to support in high stress swell-broken rock is urgent issue to solve." Combining with the project that" study on rock mechanics problems of deep mining in second mine block in the Jinchuan mine ", the following are main researches:(1) Based on previous geological survey information, the geological condition in second mine block in the Jinchuan mine is detailed surveyed and system-depth investigate. The author argues that the strength of the rock is low and rock mass' is high, and rock mass can creep. Those are the characters of soft rock;(2) According to research, the reason for the deformation and failure of deep tunnel can be get: nodal section and fissure in deep tunnel rock up growth, a large part of rock belong to fracturing structure. Because of high level ground stress and dynamic environment of mining, surrounding rock take on fracturing, expansive and creep character. Deformation includes the slip, dislocation along structural surface of fracturing rock, extension of fissure and etc.(3) Test the nature of rock mechanics through a large number of interior rock mechanics experiments. The modified expressions for Hoek-Brown strength criteria are brought based on integrality coefficient. The mechanical parameters of rock mass are logically determined;(4) Based on elasto-plastic theory, the deformation of surrounding rock and support effect in three support programs can be analyzed by midas GTS analysis software of finite element. And also give relevant evaluation for each program.(5) This article holds that the joint support of U-formed arched falsework and bolts in bottom is more reasonable in deep tunnel in second mine block in the Jinchuan mine, and puts forward some proposals about soft rock surround deep tunnel.