深部大断面巷道围岩注浆加固技术研究与应用

Research and application of grouting reinforcement technology for surrounding rock of deep roadway with large section

针对深部大断面巷道支护成型后服务期间围岩变形比较严重,巷道顶底板和两帮变形量较大等问题,基于莫尔-库仑准则和力学平衡原理,对巷道围岩注浆改性机理及巷道围岩注浆力学模型进行分析;采用FLAC 3D数值模拟方法对比分析了分层掘进、一次见顶见底掘进、注浆加固与未注浆加固,4种交叉支护方法下围岩塑性区、应力场及围岩移近量演化规律。结果表明:注浆加固后巷帮塑性区破坏范围及围岩移近量明显减小,有效控制了巷道围岩变形。定性分析并确定了“分层掘进+滞后高压注浆+强力锚索支护”的矿压控制方案,实际应用结果表明该方法能够有效控制巷道围岩变形,可为深部大断面围岩巷道注浆加固的设计与应用提供借鉴。

In view of the problem that the deformation of surrounding rock during the service period after the formation of deep roadway with large section is relatively serious,the deformation of the roof and bottom plate and the two sides are relatively large,based on Mohr-Coulomb criterion and mechanical balance principle,the grouting modification mechanism and the grouting mechanical model of surrounding rock are analyzed;FLAC 3D numerical simulation is used to compare and analyze the layered tunneling,top to bottom tunneling at one time,grouting reinforcement and non-grouting reinforcement,as well as the evolution law of surrounding rock plastic zone,stress field,and surrounding rock displacement under this four cross support methods.The results show that after grouting reinforcement,the damage range of the plastic zone and the displacement of surrounding rock are significantly reduced,which effectively controls the deformation of surrounding rock of the roadway.The rock pressure control scheme of“layered tunneling+hysteretic high pressure grouting+strong anchor cable support”is qualitatively analyzed and determined.The practical application results show that this method can effectively control the deformation of roadway surrounding rock,which can provide a reference for the design and application of grouting reinforcement for surrounding rock of deep roadway with large section.