Stability of undercut space in fragment orebody based on key block theory  

基于块体理论的碎裂矿段底部结构空间的稳定性（英文）

作　　者：胡建华[1,2] 杨春[1,2] 周科平[1,2] 李杰林[1,2] 高峰[1,2] 

机构地区：[1]中南大学资源与安全工程学院,长沙410083 [2]湖南省深部金属矿开发与灾害控制重点实验室,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2016年第7期1946-1954,共9页中国有色金属学报（英文版）

基　　金：Project(2015CX005)supported by Innovation Driven Plan of Central South University,China;Project(2016zzts451)supported by the Graduate Innovation Fund of Central South University,China;Project(2016JJ21)supported by the Fundamental Research Funds for the Hunan Province,China;Project(2012BAB14B01)supported by the National Science and Technology Pillar Program during the 12th Five-year Plan Period of China

摘　　要：Undercut is one kind of important spaces to place the mining blocks in the mass underground mining. This structure is also used as a compensation space during blasting. In the process of underground mining in the fragment orebody, it is important and critical to analyze the stability and blockage of the three-dimensional wedges created around the undercut space. The wedge stability is mainly controlled by factors including geometry （i.e., the size, shape and spatial location of the wedge and undercut）, the strength （shear and tensile） of the discontinuities that created the wedge, and the stress distribution within the rock mass. The Unwedge software was used to conduct the orthogonal simulation tests （three factors and five levels） that considered different cross sections, trends, and plunges of the undercut space. The results demonstrate that the control value of the safety factor of wedge is set to be 1.2. The optimal parameters are determined in the undercut space, such as the blasting fragmentation, orientation of the fluid flow, and the equipment gradeability;the wedge stability can be evaluated in the light of the block images and continuous falling;the stability of the key block meets the needs of the undercut space, the parameters gained are reasonable and optimal. Cross section is 27°, trend is from 315°to 325°（it is 320°at in-suit test） and plunge is 5°.底部结构是地下矿山规模开采的重要工程结构和爆破补偿空间。在碎裂矿段的地下采矿过程中,对底部空间的块体结构和三维岩石楔体开展稳定性分析是采矿成功的关键。楔体的稳定性主要由地质因素（包括底部结构与楔体的工程尺寸、形状和空间位置）、产生楔体结构的不连续面的剪切强度和抗拉强度以及岩体应力分布控制。应用Unwedge软件,设计横断面夹角、底部结构走向和倾角3因素、5水平的正交试验,获得底部结构的优化设计参数。研究结果表明：地下空间的安全系数为1.2,底部结构的参数优化由爆破块度、水流方向和设备爬坡能力决定;楔体的稳定性根据块体形状和连续冒落进行分析;优化参数为断面夹角27°、走向315°~325°、倾角5°,满足底部结构空间块体安全稳定性要求,是合理优化的设计参数。

关 键 词：wedge stability fragment orebody UNDERCUT Unwedge software optimization 

分 类 号：TD803[矿业工程—矿山开采] TD311