破碎岩层硐室连接处帷幕注浆——长锚索联合支护技术

Combined Technique of Curtain Grouting and Long Anchor Cable at the Joint of Fractured Rock Chamber

钟九铁矿矿区水文地质条件复杂,矿床顶、底板岩性以姑山组和周冲村组为主,矿区围岩主要为Ⅳ类基岩,岩体完整性较差。该矿工程副井施工井下开拓工程中,-550 m水平水泵房硐室断面跨度大且围岩破碎,加之周边水仓爆破扰动,导致-550 m水平中央变电所与水泵房硐室连接处顶板围岩出现不同程度的开裂、变形、沉降,甚至有冒落风险。对此,融合帷幕注浆与锚索支护技术优势,提出了帷幕注浆—长锚索联合支护与加固技术,并对具体的施工技术方案进行了设计。该技术基本思路是充分利用注浆帷幕将破碎顶板胶结成一个整体,然后采用长锚索将连接处顶板固定到稳定岩层上,最后通过扩刷方式完成中央变电所与水泵房的连接。根据上述技术思路,详细讨论了不同位置的帷幕注浆与长锚索支护的关键技术参数设计,并通过数值模拟耦合分析方法,对帷幕注浆与长锚索支护效果进行了详细分析。研究表明:通过进行帷幕注浆施工,能够在连接处顶板及两帮围岩形成加固帷幕,大幅改善连接处的围岩性质,通过进一步施工长锚索支护,围岩变形和破坏可得到有效控制。所提出的联合支护技术方案及相关技术参数设计,对于类似矿山井下围岩稳定性控制有一定的参考价值。

The hydrogeological conditions of the Zhongjiu Iron Mine are complex,the top and bottom lithology of the de-posit are mainly Gushan Formation and Zhouchongcun Formation,and the surrounding rock of the mine is mainly class IV bed-rock with poor rock integrity.In the underground development project of the auxiliary shaft construction of the mine project,the-550 m horizontal water pump room has a large section span and the surrounding rock is broken,and the disturbance of the surrounding water silo blasting leads to the cracking,deformation,settlement of the top wall rock at the connection between the-550 m horizontal central substation and the water pump room,and even the risk of falling.In this regard,combining the tech-nical advantages of curtain grouting and anchor cable support,the combined support and reinforcement technique of curtain grouting and long anchor cable is put forward,and the concrete construction technical scheme is designed.The basic idea of this technique is to make full use of the grouting curtain to cement the broken roof into a whole,and then use a long anchor ca-ble to fix the joint roof to the stable rock,and finally complete the connection between the central substation and the water pump house by expanding the brush.According to the above technical ideas,the design of key technical parameters of curtain grouting and long anchor cable support at different positions is discussed in detail,and the effect of curtain grouting and long anchor cable support is analyzed in detail by numerical simulation coupling analysis method.The study results show that through curtain grouting construction,the reinforcement curtain can be formed on the roof of the joint and the two sides of the surrounding rock,and the properties of the surrounding rock at the joint can be greatly improved.The proposed combined sup-port technology scheme and related technical parameter design have a certain reference value for the stability control of under-ground surrounding rock in similar mines.