节理倾角对巷道围岩的劣化效应及围岩分区域控制研究

Study on the effect of joint dip angle on roadway deterioration and regional control of surrounding rock

为解决节理发育巷道围岩控制难题,采用理论分析、数值模拟和现场实测的方法,研究节理倾角对巷道围岩的劣化效应,分析节理发育大断面回采巷道围岩的变形特征和发展规律。研究结果表明:节理弱化了岩体强度,使岩体呈现各向异性,节理发育巷道围岩呈现碎块化、低承载力和弱稳定性;小节理角度(0°~45°)发育的岩体在载荷作用下节理扩展成拉裂纹,后发生张拉破裂、翻转转动,岩体呈现显著的拉及拉剪混合破坏,使得矿山巷道岩体灾变失稳。提出了节理发育围岩分区域控制原则,以及以围岩改性加固、锚网索联合支护为主的控制技术,实测巷道顶板最大下沉量为120 mm,两帮最大移近量为90 mm,巷道变形量较小,节理发育的巷道围岩变形得到了有效控制。

In order to solve the problem of surrounding rock control of joint development roadway,theoretical analysis,numerical simulation and field measurement methods were used to study the deterioration effect of joint dip angle on roadway surrounding rock,the deformation characteristics and development law of surrounding rock of large section roadway with joint development were analyzed.The results show that the joint weakens the strength of the rock mass and make it appear anisotropy,the surrounding rock of jointed roadway presents fragmentation,low bearing capacity and weak stability;rock masses with small joint angle(from 0°to 45°)develop joints into tensile cracks under load,and then tensile fracture,overturning and rotation occur,so the rock masses exhibit significant mixed tensile and shear failure,which makes the rock mass in the mine roadway catastrophically unstable.This paper puts forward the principle of regional control of surrounding rock in joint development and the control technology of modified reinforcement of surrounding rock and combined support of anchor,net and cable.The maximum subsidence of the roadway roof is 120 mm,and the maximum movement of the two sides is 90 mm,the deformation of roadway is small and the deformation of surrounding rock with joint development has been effectively controlled.