整合矿区复杂破碎围岩及矿柱稳定性分析
发布时间：2019-05-23 01:18
【摘要】：随着我国金矿床开采工业品位的降低,采空区周边残留的低品位矿体具有了开采经济价值。由于大量采空区的存在,导致矿山开采条件恶化,回采残矿体过程中容易出现巷道失稳、矿柱变形破坏和采场坍塌等问题,严重威胁矿区作业人员和设备的安全。如何实现采空区周边残矿体安全开采是当前矿山企业亟待解决的难题。论文以某金矿山整合矿区残矿体为研究对象,在综合分析国内外资料的基础上,通过现场调查、理论研究、数值分析、工程验证等方法,对复杂破碎围岩及矿柱稳定性等关键问题开展研究,为矿山复杂破碎残矿体创建安全开采环境,指导残矿体安全回采。取得的主要研究成果如下:(1)通过对整合矿区岩体的现场踏勘,明确了节理裂隙的分布特征;采用岩体基本质量分级法(BQ)、岩体质量力学分级法(RMR)分别对矿区岩体进行质量分级和评价。(2)利用板裂结构理论和数值模拟相结合的方法,分析围岩应力的变化规律和巷道的安全性。采动应力作用是上盘巷道失稳的主要诱因,上盘巷道围岩垂直应力超过巷道围岩溃屈破坏极限应力。(3)在板裂结构力学模型分析的基础上,结合正交数值计算的方法,明确了影响巷道安全系数(F)的各要素的敏感性大小顺序为:节理间距、巷道埋深、巷道与采空区距离;利用多元非线性回归方法构建了巷道安全系数预测模型,现场工程验证表明,计算值与实际值相对误差为4.4%,模型具有较高可靠性;建议1200m中段重新布设的巷道距离采空区不少于64.1m(F1.2)。(4)基于动态强度折减方法,研究矿柱渐进失稳演变规律。通过折减计算,破损区首先出现在矿柱4个边角部位,逐渐向底部中心区域扩展,直至贯通整个矿柱;依据破损单元数量增长趋势将破损区可分为稳定、扩展、突变等3个演变过程。现场位移监测结果验证了分析结果的正确性。(5)考虑外部荷载对矿柱稳定性的影响,构建矿柱力学分析模型,根据矿柱极限强度与荷载的比值确定矿柱的安全系数(K)。现场工程分析表明,1420m中段57~59线残矿采场,当预留矿柱宽度为8m,高度为12m时,采场处于稳定状态(K=1.62);随着矿柱高度的增加,矿柱相应安全系数值会降低,当矿柱高度达到30m时,K=1.27,仍满足残矿安全开采的基本要求。
[Abstract]:With the decrease of industrial grade of gold deposits in China, the residual low-grade orebodies around goaf have economic value in mining. Due to the existence of a large number of goaf, the mining conditions deteriorate, and the roadway instability, pillar deformation and stope collapse are easy to occur in the process of mining residual orebody, which seriously threatens the safety of operators and equipment in mining area. How to realize the safe mining of residual orebodies around goaf is an urgent problem to be solved in mining enterprises. This paper takes the residual orebody of a gold mine mountain integrated mining area as the research object, on the basis of comprehensive analysis of domestic and foreign data, through field investigation, theoretical research, numerical analysis, engineering verification and other methods. The key problems such as complex broken surrounding rock and pillar stability are studied in order to create a safe mining environment for complex broken residual orebodies and guide the safe mining of residual orebodies. The main research results are as follows: (1) through the field exploration of rock mass in the integrated mining area, the distribution characteristics of joint fissures are clarified; The rock mass quality classification method (BQ), rock mass mechanics classification method (RMR) is used to classify and evaluate the rock mass quality in mining area respectively. (2) the method of combining plate crack structure theory with numerical simulation is used. The variation law of surrounding rock stress and the safety of roadway are analyzed. The action of mining dynamic stress is the main inducement of the instability of the upper roadway, and the vertical stress of the surrounding rock of the upper roadway exceeds the ultimate stress of collapse and flexion of the surrounding rock of the roadway. (3) on the basis of the analysis of the mechanical model of the plate crack structure, combined with the orthogonal numerical calculation method, It is clear that the order of sensitivity of each factor affecting roadway safety factor (F) is as follows: joint spacing, roadway buried depth, roadway and goaf distance; The prediction model of roadway safety factor is constructed by using multivariate nonlinear regression method. The field engineering verification shows that the relative error between the calculated value and the actual value is 4.4%, and the model has high reliability. It is suggested that the distance between the roadway rearranged in the middle of 1200 m and goaf is not less than 64.1 m (F1.2). (4). Based on the dynamic strength reduction method, the evolution law of progressive instability of pillar is studied. Through the calculation of reduction, the damaged area first appears in the four sides and corners of the pillar, and gradually expands to the center area of the bottom until it runs through the whole pillar. According to the increasing trend of the number of damaged units, the damaged area can be divided into three evolution processes: stability, expansion and mutation. The field displacement monitoring results verify the correctness of the analysis results. (5) considering the influence of external load on the stability of the pillar, the mechanical analysis model of the pillar is constructed, and the safety factor (K). Of the pillar is determined according to the ratio of ultimate strength to load of the pillar. The field engineering analysis shows that when the width of the reserved pillar is 8 m and the height is 12 m, the stope is in a stable state (K 鈮，
本文编号：2483467
[Abstract]:With the decrease of industrial grade of gold deposits in China, the residual low-grade orebodies around goaf have economic value in mining. Due to the existence of a large number of goaf, the mining conditions deteriorate, and the roadway instability, pillar deformation and stope collapse are easy to occur in the process of mining residual orebody, which seriously threatens the safety of operators and equipment in mining area. How to realize the safe mining of residual orebodies around goaf is an urgent problem to be solved in mining enterprises. This paper takes the residual orebody of a gold mine mountain integrated mining area as the research object, on the basis of comprehensive analysis of domestic and foreign data, through field investigation, theoretical research, numerical analysis, engineering verification and other methods. The key problems such as complex broken surrounding rock and pillar stability are studied in order to create a safe mining environment for complex broken residual orebodies and guide the safe mining of residual orebodies. The main research results are as follows: (1) through the field exploration of rock mass in the integrated mining area, the distribution characteristics of joint fissures are clarified; The rock mass quality classification method (BQ), rock mass mechanics classification method (RMR) is used to classify and evaluate the rock mass quality in mining area respectively. (2) the method of combining plate crack structure theory with numerical simulation is used. The variation law of surrounding rock stress and the safety of roadway are analyzed. The action of mining dynamic stress is the main inducement of the instability of the upper roadway, and the vertical stress of the surrounding rock of the upper roadway exceeds the ultimate stress of collapse and flexion of the surrounding rock of the roadway. (3) on the basis of the analysis of the mechanical model of the plate crack structure, combined with the orthogonal numerical calculation method, It is clear that the order of sensitivity of each factor affecting roadway safety factor (F) is as follows: joint spacing, roadway buried depth, roadway and goaf distance; The prediction model of roadway safety factor is constructed by using multivariate nonlinear regression method. The field engineering verification shows that the relative error between the calculated value and the actual value is 4.4%, and the model has high reliability. It is suggested that the distance between the roadway rearranged in the middle of 1200 m and goaf is not less than 64.1 m (F1.2). (4). Based on the dynamic strength reduction method, the evolution law of progressive instability of pillar is studied. Through the calculation of reduction, the damaged area first appears in the four sides and corners of the pillar, and gradually expands to the center area of the bottom until it runs through the whole pillar. According to the increasing trend of the number of damaged units, the damaged area can be divided into three evolution processes: stability, expansion and mutation. The field displacement monitoring results verify the correctness of the analysis results. (5) considering the influence of external load on the stability of the pillar, the mechanical analysis model of the pillar is constructed, and the safety factor (K). Of the pillar is determined according to the ratio of ultimate strength to load of the pillar. The field engineering analysis shows that when the width of the reserved pillar is 8 m and the height is 12 m, the stope is in a stable state (K 鈮，
本文编号：2483467
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