Study Of Numerical Simulation On The Exploitation Of Barrier Pillar In Deep Mine

Over the years, it mainly relies on the method of multiple, semi-empirical experience to analyze the rock stability problems, however, some potential insecure elements are difficult to be revealed. This method can not meet the needs of the actual engineering with the increasing project size and complexity, it can not effectively solve the stability problems in rock engineering. The need to determine the stress and strain around the excavation and changes in the excavation process is often encountered in rock mechanics problems in geotechnical and underground engineering, it can provide reliable quantitative basis for the design and construction. However, the existed theories can only solve such a simple round or oval holes on stress and strain fields, the complex geometry of the holes, such as mining field problems, can only be approximated by numerical simulation solution. With the development of analysis software, numerical simulation method has made substantial progress, and has become an important means in rock mechanics research and engineering calculations.Before the excavation of the third step, the barrier pillar in Dongguashan Copper Mine, we have excavated a large scale of the first steps and the second steps, so the mining technology conditions have essentially changed. First, the medium around the barrier pillar are turned into tailings backfill, which have low strength or little plastic strength. Secondly, due to the affect of the pressure transfer, the stress within the barrier pillar have been significantly increased, the mine fractured rock mass may be a lot of secondary development. In short, when excavating the third steps, the technical conditions of mining is more seriously deteriorated than it in the first steps and the second steps.The main research content of this paper are the mining technical conditions of the barrier pillar after the large-scale mining effect, and the numerical simulation about the reasonable structure size of the barrier pillar. Contents include the following:(1) Ascertaining the basic form of mass failure after the research of rock failure mechanism in deep mine. Then discussing and analyzing the rock mass failure. (2) Analyzing the technical and economic conditions of the stay barrier pillar level room subsequent filling mining method, analyzing the technical complexity of the excavation of barrier pillar.(3) Selecting six factors of affecting the barrier pillar stability, in accordance with the principle of orthogonal design, arranging 8 kinds of numerical simulation test program.(4) Analyzing the barrier pillar's mining technical condition by applying FLAC3D numerical simulation software. Complete the 8 kinds of numerical simulation test program, and compare the maximum stress values and discipline under the various programs, and then analyzes the stability of surrounding rock state. At last, obtain the weight of the six factors on the barrier pillar's stability by orthogonal analysis.(5) According to the weight of 6 factors obtained in the orthogonal numerical simulation, and combined with the technical and economic conditions in Dongguashan Copper Mine, propose an optimum scheme of the structure parameters in the excavation of barrier pillar.