Numerical Simulation On Effect Of Mining Of XI# Ore Body On Stability Of Main Shaft At Xincheng Gold Mine

Generally, mines take the method of reserving shaft pillars, namely, delineating a security boundary on the base of rock movement angles according to relevant specification to protect the shafts. For shallow underground mines, this approach can ensure the stability of shafts with few resources waste. However, the situation is quite different for deep mines, not only because of the lack of rock movement angles in deep mines, but also for the reason that delineating shaft pillars according to the specification means a waste of a large number of high quality resources. With mining depth increasing, the shafts extends deeper and deeper, the contradiction between the shaft pillars and reasonable mining is rising.This paper is based on the stability analysis of the main shaft at Xin Cheng Gold Mine as excavating the XI# ore body, including the following several aspects specifically:First of all, delineating the main shaft pillar according to relevant specification, which has been completed with the assistance of 3d-mining software. On the one hand, this process greatly simplifies the complex and redundant steps of 2d graphic method, on the other hand, it is easy to obtaine the shaft pillar boundry at any level. The shaft pillar delineated according to the specification leads to a large amount of ore could not be excavated.Then, analyzing the sensitivity of several factors that influence the shaft deformation by using of orthogonal experiment design and numerical simulation method. The results indicate that:the angle of ore body, the distance between shaft and goaf and the lateral pressure coefficient are three significant factors to the shaft deformation, the thickness of orebody and the shaft position (hanging wall or footwall) ranks secondary factors, this paper has made a preliminary exploration in the process of establishing multi-factor, comprehensive, personalized evaluation system for the shaft deformation.In addition, in order to facilitate the evaluation between the ore production and the maximum shaft deformation increment, "Mining Priority Index" (MPI) is put forward. Optimizing the mining sequence according to the MPI values, and obtaining a better shaft deformation effect. Creep analysis of the process of excavating the XI# ore body has been carried out by means of FLAC3D software, it is useful to forecast the deflection of the shaft for a long period of time.Finally, Sliding Micrometer has been applied in monitoring the main shaft deformation. Monitoring results show that:in the early mining stage, deformation of stope surrounding rock and shaft surrounding rock is very limited, moreover, it does not bring about significant tendency change up to now, which is consistent with the numerical simulation results.