三山岛金矿深部巷道围岩破坏机理及支护参数优化

随着开采深度增加,三山岛金矿深部巷道开挖后围岩变形明显,破坏现象突出,沿用传统(顶板)的支护工艺和参数已经难以满足深部巷道的支护要求。针对这一问题,采用现场踏勘、数值模拟和现场试验等手段开展研究。首先,分析了深部岩体开挖卸荷、结构面发育程度以及当前支护手段等因素对巷道变形破坏的影响,认为高应力下开挖卸荷所产生的应力松弛是导致深部巷道变形和破坏的根本原因。其次,提出了改进(顶板+两帮)的支护方案,并通过数值模拟的手段对不同支护参数进行对比分析,数值模拟结果显示,当锚杆间距为1.2m,排距为0.8m时,围岩右帮位移减少48.29%,塑性区体积减少58.23%,取得了最优支护效果。最后,将该支护方案和参数应用于三山岛金矿西山分矿-900m分段联络巷支护中,结果表明:新的支护方案实施后,围岩没有出现明显的变形和破坏,保证了巷道的稳定性。研究结果可为该类蚀变岩型金矿床深部巷道支护设计提供参考和借鉴。

Failure Mechanism and Supporting Parameters Optimization of Deep Roadway Surrounding Rock in Sanshandao Gold Mine

With the increase of mining depth,the deformation and the damage phenomenon were obvious and promi nent after the excavation of deep roadway in Sanshandao Gold Mine. It is hard to meet the supporting requirements of deep roadway by using traditional supporting technology and parameters. In view of this problem,researches were carried out by us ing field investigation,numerical simulation and field tests. Firstly,the influencing factors such as excavation unloading of deep rock mass,development degree of structural plane and current supporting means on the deformation and failure of road way is analyzed. It is considered that the stress relaxation caused by excavation unloading under high stress is the fundamental cause for deformation and failure of deep roadway. Secondly,an improved supporting scheme was put forward. Different sup porting parameters were compared and analyzed by means of numerical simulation. The result showed that the displacement of the right sidewall of the surrounding rock was reduced by 48.29%,and the volume of the plastic zone was reduced by 58.23% when the bolt spacing was 1.2 m and the row spacing was 0.8 m,with optimal support effect obtained. Finally,this support scheme and related parameters were applied to - 900 m sublevel roadway supporting in Xishan mine of Sanshandao Gold Mine. The result showed that there was no obvious deformation and damage of the surrounding rock after the new supporting scheme has been applied,ensuring the stability of roadway. This research can provide reference for deep roadway support de sign of the altered rock type gold deposit.