极软弱地层井巷工程建设关键技术研究

Research of key technology for roadway construction in ultra-soft Formation

由于中国西部地区特殊的成岩环境和沉积过程,在西部矿区广泛分布着中生代侏罗系、白垩系极弱胶结地层,具有成岩时间晚、胶结差、强度低、易风化、遇水泥化崩解的特点,是一类特殊软岩;巷道围岩自稳能力差、自稳时间短,开挖后易出现大变形、强底臌、冒顶等工程灾害,严重影响了矿井建设与安全高效生产。针对蒙东五间房矿区特殊的工程与地质条件,综合运用极软岩物理力学性质试验、巷道围岩松动圈测试、理论分析、数值模拟计算、矿压监测及工程实践等技术手段,提出了极软弱地层斜井井筒、开拓与回采巷道支护对策及施工措施,并成功指导工程实践,保证了斜井井筒与巷道的施工安全及围岩的稳定;基于回采巷道断面形状的优化分析与锚固平衡拱理论,提出了应用切圆拱形断面与双层锚固平衡拱结构,保证了回采巷道围岩与支护结构的长期稳定及安全,取得良好的经济技术效益。系统总结了极软弱地层井巷工程建设关键技术,较好地解决了极软弱地层中斜井井筒与巷道围岩稳定控制的难题。

Due to the special diagenetic environment and depositional process in western China,the ultra-soft formations which began to develop about Mesozoic Jurassic and Cretaceous are widely distributed in the western mining areas.They have the characteristics of late diagenesis,poor cementation,low strength,easy weathering and disintegration.Thus it is a kind of special soft rock.The surrounding rock of the roadway has poor self-stability ability and short self-stabilization time.After the excavation,it is prone to major disasters such as large deformation,strong floor heaving and roof falling,which seriously affects mine construction and safe and efficient production.According to the special engineering geological conditions of Wujianfang mining area in east Inner Mongolian area,the technical means of physical and mechanical properties test of ultra-soft rock,roadway surrounding rock loose circle testing,theoretical analysis,numerical simulation,mine pressure monitoring and engineering practice were integratedly used.The measures and construction means of inclined shaft development and roadway supporting in ultra-soft strata were proposed and successful in engineering guide,and the construction safety and surrounding rock stability were ensured.Based on roadway section shape optimization analysis and anchorage equilibrium arch theory,application of circle arch section and double anchorage equilibrium arch structure were put forward.The long-term stability and security of roadway surrounding rock and supporting structure were realized and good economic benefit was achieved.The key technology of roadway construction in the ultra-soft formation was systematically summarized,and the problem of inclined shaft and roadway stability in ultra-soft formation was solved.