焦家金矿巷道围岩松动圈测试与破碎岩体支护技术

Field Detection of Roadway Surrounding Rock Loose Zone and Support Technology of Broken Rock Mass in Jiaojia Gold Mine

为了准确测定破碎蚀变岩体条件下巷道围岩松动圈范围,选择合理的支护方案与参数,本项目以山东黄金集团焦家金矿为依托矿山开展研究。联合采用岩体超声探测与数字全景钻孔摄像手段,获得了焦家金矿破碎岩体条件下的巷道围岩松动圈范围为1.0~1.3 m。开展焦家金矿现场岩体质量分级,基于分级结果计算破碎蚀变岩体所需支护载荷大小。计算结果表明,在破碎岩体条件下围岩所需支护载荷为51.08~76.17 kPa。依据围岩松动圈测试结果以及围岩支护载荷计算结果,初步确定焦家金矿破碎蚀变岩体应采用管缝锚杆+金属网+喷射混凝土联合支护方案,管缝锚杆长1.8 m,设计锚杆间距为1.0 m,排距为1.2 m,喷射混凝土厚度为50 mm。在此基础上,开展支护方案的现场工业试验,由巷道围岩连续收敛监测结果表明,当应用管缝锚杆+金属网+喷射混凝土联合方案支护后,巷道围岩收敛变形在6个月内不再增长,可有效保证焦家金矿巷道围岩在服务周期内的稳定性。

In order to accurately determine the range of surrounding rock loose zone under the condition of broken and altered rock mass,and choose reasonable support scheme and parameters,researches are carried out with the Jiaojia Gold Mine of Shandong Gold Group as engineering background. Combined with rock mass ultrasonic detection and digital panoramic borehole imaging,the range of surrounding rock loosening zone of the drift under the condition of broken rock mass of Jiaojia Gold Mine is determined as 1.0~1.3 m. The rock mass quality classification of Jiaojia Gold Mine is carried out,and the surrounding rock support load is calculated based on the classification results. The calculation results show that the surrounding rock support load under broken rock mass is ranging from 51.08 kPa to 76.17 kPa. According to the field detection results of surrounding rock loose zone and the calculation results of surrounding rock support load,the joint support scheme of split bolts,metal mesh and shotcrete is proposed with the length of split bolt at 1.8 m,the design spacing and row of bolts at 1.0 m and 1.2 m respectively,and the thickness of sprayed concrete at 50 mm. On this basis,on-site industrial tests of the support scheme are carried out. The continuous convergence monitoring results of the roadway surrounding rock show that the convergence deformation will not increase within 6 months after the joint support of bolt+metal mesh+shotcrete,which can effectively guarantee the stability of the roadway surrounding rock in the service period of Jiaojia Gold Mine.