The Application Of Digital Simulating Method In The Optimization On Mining System Design Of Block Stoping

Underground mining is usually carried out near the surface in the stratum , and the object of it researching is rock mass . Rock mass are always very complex geologic structural bodies ,which are composed of various rocks . But the mineral ingredients they contains are different, and the mechanical characters they display are not the same . In other way , in the early day of the rock mass formed and the following long geologic time , because they had experienced structural movement many times , they have been become pieces , and formed complex fracture system . According to these , rock mass are very complex bodies , and they are not even , not continuous and they have various character in various way , so they show complicated non-linear .In addition , the stratum where underground mining exits virgin stress , which affects the stability of mining system directly and greatly during mining . Thus ,different mining methods , different block structural parameter and different drawing way influence the stability of mining system .Among all the mining methods , block stoping method is applied commonly in the mines about nonferrous metal, chemical engineering , gold because of its simple method , lower cost , higher productivity , lower ore dilution ratio . To block stoping ,mining system design mainly includes design of block parameter , design of pillar's dimension , design of ore drawing sequence . In the past, the main design method was analogy ,and whether the design is reasonable depends on the experience of designers . Because of different mines and rock's various characters , differentdesigners according to their different experience do not the same design . The designs always were apart away from the reasonable design . The designs were conservative and leaded to cost increasing , or were tending to extremes and caused mining system's stability lower , and even the system were destroyed .With the development of computer , the digital simulating method has been applied in underground mining .The topic of this article is just about it. After analyzing the common methods of optimizing the mining systems , and studying the characters of digital simulating methods , the author put forward the common method , principles and procedure of digital simulating method applied in mining system. For example ,the author applied the large 3 dimension FEM program named 3D-sigma and build up the models of physics ,of shape and of calculating or analyzing after studying the characters of rock and ore ,and the condition of extracting ,and the distribution of caves. Then he set up 9 models of possible extracting plan and calculated and analyzed .By comparing the stress , translocation etc of the 9 models, the author drew the conclusion of the optimizing on mining system design.In the past, the digital simulating method was applied to design in cutting and supporting by 2 dimension program , while they were little applied to design the mining system . In this paper, the author applied the large 3 dimension FEM program to simulate the block stoping's block parameter and ore drawing sequence in the mining system design about -5 80m level of Datusan field in Shizishan Copper mine , and attained to good effect.