露天转地下开采精细模拟及境界顶柱方案优选

Fine simulation of transferring open pit into underground mining and schemes optimization of boundary pillar

基于3Dmine构建的矿体、地表DTM模型，与Midas／GTS耦合操作生成精细的露天转地下几何模型，结合矿山实际提出复合境界顶柱的概念，采用FLAC3D对5种境界顶柱方案的几何模型进行模拟，并从位移场和应力场两方面对境界顶柱安全性及破坏方式进行分析，模拟结果显示境界顶柱破坏以拉应力引起的贯穿破坏为主，混凝土能够很好地约束境界顶柱的横向位移。减小顶柱上的拉应力，根据模拟结果选取1m混凝土和20m原岩顶柱作为境界顶柱方案。

The reasonable thickness of boundary pillars is signifi- cant to safety in production during transferring open-pit into un- derground mining, while there is no unified computing method for ensuring thickness of boundary pillars. Based on ore body modelbuilt by 3Dmine, DTM model of geography and Midas/GTS cou- pling, this paper presents the refined geometrical model of trans- ferring open-pit into underground mining. The paper also presents the structural concept of composite boundary pillar according to the actual mine, and adopts FI.AC3D simulating the geometrical model of 5 boundary pillar schemes, and also analyzes safety and breaking way from the angles of displacement field and stress field. According to the results of simulating, the main crack form of boundary pillar is run through failure causing by tensile stress, and the concrete can restrain the lateral displacement of the bound- ary pillar and decrease the tensile stress appeared on the boundary pillar, taking the boundary pillar scheme which consists of lm thickness of concrete and 20 m thickness of rock.