Research On Shotcrete Bolt Support Technology Of High Stress Broken Rock Mass In A Metal Mine

With the decreasing of the resources in shallow bed, mining depth in domestic mine has been deepening all the time, and the ratio of the use of high stress broken rock roadway has also been increased. The metal mine in the west is a most typical mine in high-stress broken rock environment. Compared with the domestic and foreign mine, the metal mining has significant characteristics such as deep, big, broken, etc. Therefore, since the beginning of the mine production, scientific research has been carried out and achieved impressive results. In recent years, however, along with the gradually increasing of mining depth, the geological environment becomes more and more complex, the rock mass is more broken together with strong tectonic stress and the influence of large section trackless haulage tunnel, roadway support and began to highlight. In the process of constructing and mining, mine roadway deformed severely, and some roadways even require repairing before bein g put into use. How to provide support in stress broken rock roadway is urgently to be solved in mining.In this paper, a metal mine 1110 west segment tunnel is chosen as the research object and has been carried out a serious researches on. Firstly, basing on the field investigation and anaylisis of related information, I summarize the characteristics and regulation of the changes of roadway. Secondly, on the basis of numerical simulation analysis result in a high stress broken rock roadway damage, I get the main reason and question existing in supporting at present. In response to these high stress broken rock roadway destruction reasons, I put forward hollow grouting prestressed anchor(2.6m) + TECCO net + shotcrete combined support program and use numerical simulation software to analyze the new support program and the original support programs. Finally, evaluate the support effect of the new plan basing on the field investigat ion and the changes of roadway.Conclued from the reaserch on the metal mine 1110 west segment tunnel, the following are known: At present, the main problem is that the length of mortar bolt is short, and the radial stress can not be provided in the early stage, and the construction quality is hard to be guaranteed. Using hollow grouting anchor(2.6m) +TECCO net and sprayed concrete combined supporting way to maintain the stability of the roadway has achieved good results, and it is getting generally stable 20 days later, and a secondary support is suggested.