金川二矿区上盘巷道变形破坏与水平矿柱的关系

金川二矿区采用大面积不留矿柱充填采矿法,开辟了不同标高的两个采矿平面,其间出现了横亘于上下盘之间的水平矿柱。在上盘围岩中,近年来尤以1178标高巷道破坏最严重,更浅处与更深处的巷道破坏较轻。在考虑构造应力场和采矿扰动的基础上,建立了分析各标高沿脉巷道与水平矿柱之间耦合影响的二维有限元模型。模拟发现,穿脉向应力集中程度越来越高的水平矿柱对上盘围岩中巷道有"抵顶作用",是造成1178巷道严重破坏的关键因素;从2005年开始,随着水平矿柱各盘区屈服破坏状态的来临,"抵顶作用"将迅速衰减,所以2006年准备建设的1158巷道的变形破坏程度会较轻,这一预言已得到现场观测的初步证实。

Effect of the Level Pillar on the Deformation and Failure of Hanging Wall Roadway in Jinchuan No.2 Mining Area

The large area mining and backfilling without intervening pillar has been successfully used in Jinchuan No.2 mine area.Now,there are two mining levels,respectively,the upper level and the down level,a level pillar has formed between them.In recent years,severe structural distortion has appeared in the hanging wall roadway at 1178 m level besides the drifts at other levels in hanging wall.Based on considering the tectonic stress field and mining disturbance,a two dimensional finite element model was established to analyze the coupling effects between the level pillar and strike roadway at different level.In simulations of model,the level pillar,in which the stress concentration in the direction across vein increases with the advance of mining,has a "counteractive effect" on the hanging wall roadway,it is the main factor causing the severe structural distortion of the roadway at 1178 m level.In 2005,it was predicted that the "counteractive effect" would gradually become weaker with the appearance of the entire yield destruct situation of the level pillar,so the deformation and failure of the roadway planed to be constructed at 1158 m level would be less than that of the roadway at 1178 m.The prediction has already been proved by the results from in-situ observations.