厚大矿体采场结构参数优化研究

Research on optimization of stope structure parameters of thick orebody

合理的结构参数对维护采场稳定、提高单个采场产能、降低采切工程量具有重要意义。以蒙库铁矿为研究对象,利用岩体遥测与结构分析系统Sirovision对采场顶板、侧帮及上盘围岩节理面进行调查和数字化识别,获取采场节理组的空间方位统计信息及优势节理产状;基于Mathews稳定图解法对沿走向布置与垂直走向布置采场的顶板、侧帮及上盘开展稳定性分析,得到采场顶板、侧帮及上盘的实际水力半径和允许水力半径的相关关系;采用数值分析方法,通过分析矿柱的位移、最大剪切应变率及采场的主应力等因素,确定了2种典型采场结构矿柱的最小安全厚度。研究结果表明:采场沿矿体走向布置时,当矿体厚度小于20 m时,长度控制在40 m之内的采场稳定性较好;采场垂直矿体走向布置时,矿体厚度不超过30 m,宽度小于25 m的采场稳定性较好;对于沿走向布置的40 m×15 m典型采场,矿柱最小安全厚度为6 m;对于垂直走向布置的30 m×25 m典型采场,矿柱最小安全厚度为8 m。研究结果可为蒙库铁矿采场结构参数优化提供依据,并能为国内外同类矿山采场结构设计提供参考。

Reasonable structural parameters are of great significance to maintain stope stability,improving the productivity of a single stope,and reducing mining and cutting quantities.Taking Mengku Iron Mine as the research object,the rock mass telemetering and structural analysis system Sirovision are used to investigate and digitally identify the joint surface of the roof,side wall,and hanging wall of the stope,and obtain the spatial orientation statistical information and dominant joint occurrence of the stope joint group.Based on Mathews graphic method,the stability analysis is carried out for the roof,side wall and hanging wall of the stope arranged along the strike and perpendicular to strike,and the correlation between the actual hydraulic radius and the allowable hydraulic radius of the stope roof,side wall and hanging wall is obtained.The minimum safe thickness of pillar for two typical stope structures is determined by numerical analysis method through analyzing the displacement of pillar,maximum shear strain rate and main stress of stope.The analysis results show that when the stope is arranged along the strike of the ore body,the thickness of the orebody is less than 20 m,and the stope length is controlled within 40 m,the stability is good.When the stope is arranged perpendicular to the strike of the orebody,and the thickness of the ore body is not more than 30 m,the stope with a width of less than 25 m has good stability.For the 40 m×15 m typical stope arranged along the strike,the minimum safety thickness of the pillar is 6 m,and for the 30 m×25 m typical stope perpendicular to strike,the minimum safe thickness of the pillar is 8 m.The research results can provide a basis for the optimization of stope structure parameters of Mengku Iron Mine and can provide a reference for the design of stope structures of similar mines.