基于松动圈理论的充填体下巷道顶板安全厚度和支护方式

 为安全高效回采冬瓜山铜矿盘区隔离矿柱,在充分利用矿山已有巷道工程的前提下,仍需在盘区采场充填体下开挖新的出矿巷道.基于松动圈理论,利用单孔声波检测仪测量巷道围岩松动圈范围,为确定充填体下开挖巷道的顶板安全厚度、选择巷道支护方式提供依据.现场测试表明,冬瓜山铜矿-760和-790m巷道的围岩松动圈为0.8~1.3m.根据圣维南局部效应原理,结合工程技术人员的实际经验,最终确定采场充填体下新开挖出矿巷道的顶板安全厚度为4m.此外,通过松动圈测定和工程借鉴,确定新开挖巷道支护采用喷锚支护,局部破碎地方采用喷锚网联合支护,经理论计算和现场实测,总结出新开挖出矿巷道顶板锚杆长度选取2.2m、锚杆网度选取1.0m×1.0m时,能够安全经济地控制巷道松动圈.

Roof Safety Thickness and Support Pattern of Roadway Under Fillings Based on Released Zone Theory

In order to mine the insulating pillar of Dongguashan copper mine safely and effectively, with the full use of existing mine roadways, new ore-drawing roadways are needed to be excavated under the filling of the panel stope. Based on the theory of the surrounding rock released zone, the roadway surrounding the rock released zone is measured by the single-hole acoustic detector, to provide the basis of the determination of the roadway roof safety thickness and the support pattern. By means of field tests, the surrounding rock released zone thickness of -760m and -790m levels is 0.8~1.3m. Combining the Saint-Venant principle and the field experience, the roof safety thickness of the new extracted ore-drawing roadway under filling is determined to be 4m. In addition, the shotcrete-bolt support pattern is adopted; as regards to the partial broken area, the spray anchor net united support pattern is adopted. As a result, when the length of the bolt for the new extracted ore-drawing roadway is determined to be 2.2m, and the grid is 1.0m×1.0m, the roadway surrounding the rock released zone can safely and economically be controlled.