白象山铁矿地下岩体结构调查及稳定性分析

Structure Investigation and Stability Analysis of Underground Rock Mass in Baixiangshan Iron Mine

随着回采范围增大,白象山铁矿地下岩体受爆破及地压变化的作用,其节理裂隙发育情况发生较大变化。因此,重新对各中段以及盘区进行岩体结构调查,并运用Q法、RMR法、BQ法对岩体稳定性做出评价分析。结果表明,井下岩体整体稳定性等级在Ⅲ~Ⅴ级,稳定性较差。在-330、-390和-430m中段的七盘区岩体稳定性均属于一般(Ⅲ级)到较差(Ⅳ级);在-390m中段一盘区和二盘区岩体稳定性属于较差(Ⅳ级),在-390 m中段五盘区和-470 m中段的二盘区属于较差(Ⅳ级)到极差(Ⅴ级)。在稳定性较好地段跨度5~10m情况下,围岩可稳定数月,在较差地段无自稳能力。

With the increase of mining range,the development of joint fissures in the underground rock mass of Baixiangshan Iron Mine has changed greatly due to blasting and ground pressure changes.Therefore,the rock mass structure of each middle section and panel is investigated again,and the stability of rock mass is evaluated and analyzed by Q method,RMR method and BQ method.The results show that the overall stability of the underground rock mass is gradeⅢ~Ⅴ,and the stability is poor.The stability of rock mass in the seventh panel in the middle section of-330 m,-390 m and-430 m belongs to general(gradeⅢ)to poor(gradeⅣ).The stability of the rock mass in the first and second plates in the middle section of-390 m is poor(gradeⅣ),and the stability of the rock mass in the fifth plate in the middle section of-390 m and the second plate in the middle section of-470 m is poor(gradeⅣ)to very poor(gradeⅤ).In the case of a good stability section with a span of 5~10 m,it can be stable for several months,and there is no self-stability in the poor section.