深井软岩硐室群支护技术研究

Study on Soft Rock Cavern Groups Support Technology in Deep Mine

为解决新河煤矿-980m水平硐室群在掘进及支护过程中的大变形问题,首先通过理论分析,研究了相邻硐室不同开挖顺序对围岩破坏的影响;其次运用FLAC^(3D)数值模拟软件对相邻硐室群的不同开挖顺序进行模拟,计算得到围岩塑性区最小破坏体积V_(P),并得出最优施工方案,在上述研究基础上对已开挖硐室群进行支护设计,提出泵房主体及壁龛前期采用锚网、注浆锚索、喷浆,后期采用钢筋混凝土砌碹的联合支护方式,并对实施该支护方案的硐室群进行支护前后的数值模拟计算,计算结果表明,水泵房主体硐室顶板最大下沉量由927mm下降至30mm,底臌量由1036mm下降至6mm,主体泵房左帮移近量由1010mm下降至10.9mm,壁龛掌面移近量由700mm下降至9.9mm,围岩变形得到有效控制.顶底板位移现场监测结果表明,监测断面两帮最大移近量为8mm,顶底板最大移近量为15mm,巷道支护效果良好,能有效控制围岩变形.

In order to solve the problem of large deformation during the excavation and support of the-980m deep chambers in Xinhe coal mine,firstly,through theoretical analysis,the influence of different excavation sequences of adjacent chambers on the failure of surrounding rock was studied.Secondly,FLAC^(3D)numerical simulation software was used to simulate the different excavation sequences of adjacent chamber groups,calculate the minimum failure volume V_(P) of surrounding rock plastic zone,and obtain the optimal construction scheme.Based on the above research,the support design was carried out,and it was proposed that anchor mesh,grouting anchor cable and shotcrete were used in the main body of pump house and niche in the early stage,the combined support method of reinforced concrete masonry was adopted in the later stage.The numerical simulation calculation before and after the support of the chamber group implementing the support scheme were carried out.The calculation results show that the maximum subsidence of the roof of the main chamber of the pump house decreases from 927mm to 30mm,the floor heave decreases from 1036mm to 6mm,and the left side approach of the main pump house decreases from 1010mm to 10.9mm,and the approach diatance of the palm surface of the niche decreased from 700mm to 9.9mm,the surrounding rock deformation was effectively controlled.The field monitoring results of roof and floor displacement show that the maximum displacement of the two sides of the monitoring section was 8mm and the maximum approach diatance of the roof and floor was 15mm.The roadway support effect was good and the surrounding rock deformation can be effectively controlled.