乌东矿急倾斜特厚煤层水平分段综放开采顶板破断特征研究

为研究急倾斜特厚煤层水平分段综放开采顶板破断特征,基于急倾斜特厚煤层工作面顶板赋存条件并结合弹性力学,建立了急倾斜特厚煤层水平分段开采顶板力学模型。通过力学模型分析,推导出急倾斜特厚煤层水平分段开采后顶板沿工作面倾向方向的岩板破断判据及挠度公式,应用三角级数方法对挠度公式进行求解,确定了顶板沿倾向方向上最大挠度发生的位置关系式。理论研究成果在乌东矿南采区B1+2急倾斜特厚煤层水平分段综放开采中的工程应用表明,工作面沿倾向方向上推进到385 m时顶板发生破断,倾向方向顶板最大挠度坐标位置为y=325.78 m,顶板沿工作面倾向方向的最大挠度位于采空区中部偏下位置。表现为急倾斜特厚煤层顶板在工作面上方的非对称性破断;相似材料试验进一步验证了顶板挠度公式的合理性。

胶结充填体-顶板系统稳定性研究

在胶结充填采矿法中,胶结充填体弹性系数和其不接顶高度是空区顶板安全的重要影响因素。基于柔性支护原理,把顶板变形分为两个阶段:顶板在覆岩自重应力作用下产生挠曲变形;顶板与胶结充填体接触后共同承载顶板覆岩自重应力;并据此分别建立了力学模型。以广西盘龙铅锌矿为工程分析实例,研究在不同胶结充填体弹性系数和不接顶高度条件下顶板挠度的变化规律。结果表明:当胶结充填体弹性系数k≥0.1 GN/m3时,不接顶高度h是影响顶板挠度的主要因素,当胶结充填体弹性系数k较小时,弹性系数k是影响顶板挠度的主要因素;当k≥0.1 GN/m3且h≤300 mm时,胶结充填体能有效控制顶板岩层移动和降低储存在其中的应变能。现场勘探结果与理论计算基本吻合,验证了研究成果的可靠性。

急倾斜煤层充填机理梁式模型力学分析

针对在"三下"采煤或要求避免地表下沉量较大的工作面开采,通常采取采空区充填的开采方法。从力学梁式理论的角度分析采空区充填后工作面顶板受力特征,引入充填长度及顶板支撑均布载荷两参数,探讨了采空区充填范围以及填充材料在不同的压实程度过程中对工作面顶板挠曲下沉的影响,给出顶板挠曲计算式。并从数值分析的角度给出工作面顶板在采空区不同充填状态下的位移特征,说明采空区填充对工作面顶板挠度的影响。

Analytical solutions of hard roof's bending moment,deflection and energy under the front abutment pressure before periodic weighting

The distribution of front abutment pressure is closely related to the force,deformation and energy distribution of hard roof before periodic weighting. So it is necessary to carry out research on the relationship between them. According to front abutment pressure distribution feature,using the location of peak front abutment pressure as the dividing point,coal seam is divided into two parts along the direction of mining: the yield zone that is the area between the faceline and the point where the maximum front abutment pressure occurs,and the elastic zone that is the part before the point of peak front abutment pressure. The proposed mechanical model of unit width hard roof at the panel center before periodic weighting consists of five parts including the yield zone. All parameters of the deflection equations for each of the five parts that satisfy the continuity conditions and natural boundary conditions are obtained by using the Matlab software. The continuous curves of front abutment pressure,deflection,bending moment and bending strain energy density distribution of hard roof are obtained by iterative approximation method,and the relationship between the yield zone width and the above curves are analyzed in detailed.

迎采掘进巷道合理煤柱宽度确定

针对东易煤矿4102工作面回风巷道迎4101回采工作面掘进带来的巷道布置难题,综合数值模拟、理论计算等方法,对距4101工作面不同距离处的侧向支承应力分布、顶板挠度分布和不同宽度煤柱内部塑性区分布进行了分析。结果显示,支承应力和挠度值呈"驼峰状"分布;当巷道布置在挠度峰值内侧时,煤柱内部仍有弹性稳定区,保证了煤柱稳定性和承载能力;结合东易煤矿实际生产条件,最终确定了东易煤矿4102回风平巷的护巷窄煤柱宽度为7 m。