三山岛金矿新立矿区西南翼破碎岩体稳定性控制数值模拟研究

Numerical simulation for stability control of fractured rock mass in southwest flat of Xinli mining area of Sanshandao Gold Mine

三山岛金矿新立矿区属破碎带蚀变岩型特大型金矿床,区内构造主要为断裂构造。通过现场工程地质调查发现,现有支护条件下,巷道围岩会产生楔形体冒落、层状节理复合破坏和沿软弱夹层(断裂带)塌落破坏三种破坏模式;确定巷道变形破坏的主要影响因素为围岩成分及其结构构造、地下水、地压显现类型和巷道周边采掘震动。基于上述研究结果确定采用锚网喷支护方法对研究区域岩体进行支护,并给出支护方案A和B;选取-240m一中段进行建模,应用FLAC3D数值模拟软件分析无支护、支护方案A和支护方案B三种条件下围岩应力、位移和塑性区分布特征,发现支护方案A和B均能够有效控制围岩变形破坏,但方案A较方案B成本低,即方案A为合理支护方案,可用于现场工程实践。

Xinli mining area of Sanshandao Gold Mine is a super-large altered rock type gold deposit in fractured zone,and its structure is mainly fracture structure.Through field engineering geological survey,it is found that under the existing supporting conditions,the surrounding rock of roadway will produce three failure modes:wedge caving,composite failure of layered joints and collapse along weak interlayer(fault zone);the main influencing factors of roadway deformation and failure are determined to be the composition of surrounding rock and its structure,underground water,ground pressure type and excavation vibration around the roadway.Based on the above research results,bolt-mesh-shotcrete support method is adopted to support the rock mass in the study area,and support schemes A and B are given.Modeling is carried out in the-240 mlevel.Stress,displacement and plastic zone distribution characteristics of surrounding rock under three conditions of no support,support schemes A and support schemes B are analyzed by FLAC3D numerical simulation software.It is found that support schemes A and B can effectively control the deformation and failure of surrounding rock.But the cost of scheme A is lower than that of scheme B,that is,scheme A is the best supporting scheme and can be used in field engineering practice.