金川镍矿不良岩层巷道变形与支护研究

STUDY ON DEFORMATION AND SUPPORT OF ROADWAYS IN WEAK ROCKMASS IN JINCHUAN NICKEL MINE

金川镍矿是我国最大的地下有色金属矿山,该矿具有地应力高、围岩破碎的特点,巷道支护是金川镍矿面临的一个严峻的问题。介绍了金川镍矿围岩的工程地质分类、地应力的分布规律和不良岩层围岩的基本特征,总结了金川镍矿不良岩层巷道的变形破坏规律,评价了过去该矿所用的各种巷道支护方式,并介绍了金川镍矿不良岩层巷道支护的新方法:采用强力喷锚网支护作为一次支护,尽快的提供支撑抗力,有效的阻止围岩松散,并在有制约的条件下,容许围岩变形缓慢发展,使围岩应力得到一定释放。二次支护采用锚注式支护方式,使浆液注入岩体裂隙,配合喷锚支护,可以形成多层组合拱结构,扩大了支护结构的有效承载范围,改变了围岩的松散结构,提高了支护结构的整体性和承载能力。在局部围岩不稳固地段,采取喷锚网支护、网钢构架支护、U型钢拱架支护及现浇钢筋混凝土支护等措施,进一步提高支护强度,避免巷道的变形破坏。目前,这一新的支护方法已经在金川镍矿逐步推广应用。

Jinchuan nickel mine is the largest underground metal mine in China,There is highly stressed weak rockmass in this mine. The problem of roadway support in Jinchuan mine is serious. The types of rockmass is classified based on engineering geological investigation data from in-situ rock mass,The in-situ stresses,deformation laws of surrounding weak rockmass,and support methods of roadway used in the mine are presented. Using rock bolt shotcrete and wire mesh support method as a primary support,immediate support can be provided to prevent the surrounding rockmass from loosening. The presented support method also permits the surrounding rockmass to deform gradually,so that the stress of surrounding rockmass can be released to certain degree. Rock bolting and grouting serves as a secondary support. Injecting the cement grout into the cracks of the rockmass can prevent the structure of the surrounding rockmass from loosening. Therefore the self-supporting ability of the surrounding rockmass is enhanced. Moreover,using rock bolting and grouting support combined with rock bolt shotcrete and wire mesh support,multi-layer-compounding arches can be formed to increase the effective load-carrying capacity. For the roadways under high in-situ stresses,if the surrounding rockmass is stratified fractured structure or loosening structure,the primary support should be rock bolt shotcrete and wire mesh support,and secondary support should be sectional fabricated steel arch,rock bolting and grouting support,reinforced concrete support,or rock bolting and grouting together with U shaped iron bar. Generally,these measures can serve to maintain the stability of the roadway. This new technology is gradually becoming popular in Jinchuan nickel mine.