弱胶结软岩巷道支护技术研究

On the supporting technology for the case of the weakly cemented soft rock roadway in the mining system

为研究弱胶结软岩巷道支护难题,以塔然高勒矿区某矿弱胶结软岩巷道支护工程为研究对象,通过现场调研和室内试验分析弱胶结软岩遇水软化机理。利用有限元分析软件MIDAS/GTS建立弱胶结软岩巷道弹塑性数值计算模型,对比分析锚网喷和锚网喷架两种支护方案时的巷道塑性区范围、应力分布、表面位移、喷混结构受力及锚杆和钢支架的受力形态。进行现场工业试验,监测巷道围岩收敛变形和锚杆受力变化情况。结果表明,锚网喷架支护形式能够确保支护体系充分发挥作用,塑性区范围小,围岩应力分布均匀、锚喷支护结构受力均匀且较锚网喷支护时小,采用钢支架与锚网喷构成支护体系会大大提高支护结构整体刚度,提升围岩的自稳能力和自承能力。

This paper takes it as a research object to analyze the weakly cemented soft rock＇s water-softening mechanism through an on-spot investigation and laboratory experiment over the weakly cemented soft rock roadway support project of Ta-Ran-Gao-Le Mining area.Since the situation of the surrounding rock mechanics plays an essential role in the mining roadway support,it makes us feel it necessary to compare the situation of the roadway with other rocks and find the mechanical properties of the said soft rock significantly specific.Therefore,great efforts are to be made to study and solve the difficult problem of the weakly cemented soft rock roadway support by using a finite element analysis software named MIDAS/GTS and establishing an elastoplastic numerical simulation model.In doing so,we have made a comparative analysis of the range of plastic zone of the roadway,the stress distribution,the displacement of the roadway surface,the stress pattern of the spray mixed structure,bolt and steel trestles under the two support schemes of the anchor net spray and the anchor net spray frame.At the same time,we have also conducted the field industrial tests for monitoring the convergence deformation of the surrounding rock or rocks of the roadway and the bolt stress changes.The simulated research results show that the support form of the anchor net spray frame can help to ensure the full function the system plays.Under the condition of a smaller range of plastic zone of roadway,the uniform distribution of the roadway surrounding rock stress,the uniform structure support by the rock bolt and shotcrete with the smaller anchor net spray support,it is possible for the steel bracket and anchor net spray support system to improve the entire stiffness of the support structure greatly,thus,guaranteeing and enhancing the stability and bearing capacity of the roadway surrounding rock.Therefore,the results we have gained can be expected to provide a valuable reference for the roadway support issues under the above said soft rock geological conditions in the mining area,which is entitled with great engineering significance and scientific value in the soft rock construction field.