综放沿空留巷底鼓变形及其控制研究

Study on floor heave of gob-side entry retaining in fully-mechanized top-coal caving face and its control

针对综放沿空留巷底鼓变形严重问题,分析综放沿空留巷底鼓变形规律,建立综放沿空留巷底鼓力学模型,推导出底鼓计算公式,并对其影响因素进行分析,据此提出底鼓控制对策,最后将其应用于现场。结果表明:综放沿空留巷的实际底鼓量取决于直接底压曲量与基本底挠曲量两者的最大值,底鼓量理论计算结果与现场实测结果基本一致。各因素对底鼓影响程度依次为:巷道宽度、基本底弹性模量、巷旁支护体宽度、巷旁支护体对底板压力、煤帮极限平衡区宽度、采放比。合理的底鼓控制措施应针对关键性影响因素实施,据此提出"锚网索+高强度墩柱+基本底注浆"围岩变形控制对策,现场工程应用表明,底鼓变形得到了有效控制。

Aimed at solving the serious problem of floor heave of gob-side entry retaining in fully-mecha- nized top-coal caving mining face, the authors analyzed floor heave law and established mechanics models for floor heave based on plate theory and minimum total potential energy principle. The authors worked out the calculation formulas of floor heave which were used to analyze influence factors of floor heave. And then the authors proposed floor heave control countermeasures and put them into practice. Results show that floor heave of gob-side entry retaining in fully-mechanized top-coal caving mining face is a function of both the maximum between immediate floor buckling value and the maximum basic floor flexure value, that the floor heave calculated by using the formulas is consistent with that measured in field, that main influencing factors on floor heave are roadway width, basic floor elastic modulus, supporting body width, stress of support body, coal side limit equilibrium zone width, and caving ratio, and that control countermeasures of floor heave should be taken according to the factors. Based on research results, the authors have put forward the control countermeasure of ＂bolt-net-anchor ＋ high strength pier ＋ basic floor grouting＂ coupling support. Application in the field demonstrates that the floor heave is effectively controlled.