“双软”顶底板薄煤层沿空留巷底鼓机理分析

Floor heave mechanism of gob-side entry retaining in thin coal seam with soft roof and floor

综放沿空巷道底鼓不仅造成巷道的破坏,对窄煤柱、巷旁充填体乃至整个巷道的稳定性也有重要影响,强烈的底鼓带来大量的维护和翻修工作,严重影响矿井正常的生产,大大增加了巷道的支护和维修费用。采用Winker弹性地基理论模型,建立了沿空留巷底鼓力学模型,结合工程案例,对巷道底鼓力学模型进行了验证,研究结果表明:实体煤与巷旁支护体侧底板变形接近零,巷道区域底板变形呈现为"抛物线"特征,具有非正对称现象,底鼓最大变形处位于靠近巷旁支护体侧,最大值为628mm;实测变形监测100d后底鼓量最大值为645mm,理论模型最大值与实测最大值误差为2.6%。

The floor heave of the fully mechanized gob-side roadway not only causes damage to the roadway,but also impacts on the stability of narrow coal pillars,the road-side filling body and the entire roadway.Strong floor heave brings a lot of maintenance and renovation work,which seriously affects the normal operation of coal mine production and greatly increases the roadway support and maintenance cost.So,a mechanical model of the floor heave is established for the gob-side roadway,based on Winker elastic foundation theory model,which is verified combining with engineering cases.The research results show that,there is almost no deformation in the solid coal and the floor of the road-side support,the floor deformation of the roadway area presents a non-positive symmetry parabolic curve,and the maximum deformation of the floor heave is near the road-side support body with a value of 628 mm;according to monitoring data,the maximum deformation value of the floor heave after 100 days is 645 mm,the error between theoretical model and monitoring is 2.6%.