复杂交岔点稳定性分析与钢管混凝土墩柱群支护技术

Stability analysis of complex intersection point and supporting technology of concrete-filled steel tube pier column group

  • 摘要: 巷道交岔点作为井下开采的关键部位对矿井安全生产具有全局性控制作用,针对深部复杂交岔点悬顶面积大、围岩应力集中、支护难度大等问题,以阳城煤矿−650南翼轨道大巷与联络巷交岔点为研究对象,采用理论分析、数值模拟、室内试验及现场应用等方法,系统开展了交岔点稳定性分析和复合支护技术研究。通过分析交岔点围岩地质与力学参数及变形影响因素,建立了交岔点顶板变截面梁支撑体系力学模型,推导了顶板岩梁挠度计算公式,确定了顶板跨度为影响交岔点稳定性的最重要因素,划定了交岔点顶板下沉危险区范围,提出了交岔点关键部位变形控制技术。设计了基于钢管混凝土组合支架和基于钢管混凝土墩柱群的2种交岔点复合支护方案,模拟显示采用2种支护方案后交岔点顶板分别下沉100 mm和150 mm,表明2种支护方案均能有效约束交岔点顶板下沉并保证交岔点支护安全。随后从施工难易、支护成本及允许变形量等方面开展对比分析,确定基于钢管混凝土墩柱群的复合支护方案为首选,并设计了轴压承载力试验对钢管混凝土墩柱群结构进行承载验证分析,进一步开展了工程实践,实践表明:基于钢管混凝土墩柱群的复合支护方案在−650南翼轨道大巷与联络巷交岔点实施后,顶板及围岩稳定性显著提升。现场监测显示,支护结构实施2 a和5 a后顶板的累积下沉量分别为65 mm和126 mm,小于钢管混凝土组合支架复合支护方案的数值模拟预测结果,满足交岔点使用要求,交岔点持续稳定,现场支护效果良好,且施工简单,成本经济,为复杂交岔点支护提供了良好借鉴。

     

    Abstract: Roadway intersection point are critical in underground mining and significantly impact mine safety. To address challenges such as large unsupported roof areas, concentrated stress, and difficult support in deep complex intersection point, a study is conducted at the −650 south wing track main roadway intersection point in Yangcheng coal mine. The research combines theoretical analysis, numerical simulation, indoor testing, and field application to evaluate intersection point stability and develop composite support technologies. By analyzing geological and mechanical parameters, a variable cross-section beam support model is established, and a formula for roof deflection is derived. The roof span is identified as the primary factor affecting intersection point stability, with a defined danger zone for roof subsidence. Two composite support schemes are designed: One using concrete-filled steel tube composite frame and another using concrete-filled steel tube pier column group. Simulations show roof subsidence of 100 mm and 150 mm, respectively, indicating both schemes effectively controlled subsidence and ensured safety. A comparative analysis base on construction difficulty, cost, and allowable deformation selected the concrete-filled steel tube pier column group scheme as optimal. Field implementation confirms significant improvements in roof and surrounding rock stability. Monitoring data after 2 years and 5 years show cumulative roof subsidence of 65 mm and 126 mm, respectively, lower than predictions for the concrete-filled steel tube support scheme. This demonstrates continuous stability, good support performance, simple construction, and economic feasibility, providing valuable insights for complex intersection point support.

     

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