针对平顶山矿区深部大规模松软围岩稳定性控制问题,以典型大规模松软围岩巷道为研究对象,研究确定其围岩的赋存条件,采用离散元方法模拟巷道围岩的变形破坏过程,揭示其破坏机制,提出相应的支护对策,结合深部巷道围岩稳定性控制理论拟定支护的总体思路,确定具体支护方案,研发围岩巷道的抗折抗裂喷层技术及深部巷道底臌治理技术。研究结果表明:围岩承受的高地应力与其自身低强度之间的矛盾是造成深部大规模松软围岩巷道失稳的主要原因;巷道首先在拱顶、底板中央区及两侧边墙受张拉破坏,拱肩及两侧底角受剪破坏,破坏区范围逐渐向深部扩展直至失稳。现场实测数据表明:在方案实施2个月后,锚杆、锚索受力在较高值趋于恒定,充分发挥了支护作用;水平收敛、拱顶下沉和底板臌起趋于稳定,大规模松软巷道围岩稳定性得到有效控制。
A typical deep roadway with large-scale soft surrounding rock is researched here to study the stability of surrounding rock in Pingdingshan coal mine.With the laboratory experiment,the complex geological condition in deep rock roadway was determined.Discrete element method was adopted to simulate the deformation and failure of surrounding rock.The failure mechanism of surrounding rock was revealed.Technologies of spray layer which resisted bending and cracking and floor heave control were proposed.The main reason for instability of soft surrounding rock in deep rock roadway is the lower rock strengthen and the high geostress.The tensile failure appeared at vault and two side-walls and in the middle of floor at first.Then,the shear failure appeared at spandrel and two base angles.The failure zone extended into the deep area until the roadway is instable.According to the in-situ monitor data,it is concluded that stress in anchor and cable tended to be stable after supporting for two months,as well as the horizontal convergence,vault subsidence and floor heave.It means that the supporting technology works and the stability of soft surrounding rock in deep rock roadway is controlled.