采动覆岩隔离注浆充填对关键层支撑作用的力学模型研究

发布时间：2018-11-22 08:27

【摘要】：近几年,采动覆岩隔离注浆充填技术在淮北矿区单工作面开采时得到了成功的应用并取得了良好的减沉效果。然而,在开采相邻工作面时,不可避免地引起第一个工作面上覆岩层下沉的增加,但它的内部岩移力学机理是什么却不清楚,因此本文针对这一实际问题抽象出关键层的力学模型进行分析。论文以关键层理论和弹性地基梁理论为基础,开展了采动覆岩隔离注浆充填对关键层支撑作用力学模型的理论推导,得出了如下几个主要研究成果:(1)推导出了采动覆岩隔离注浆充填体支撑作用下,单、双工作面覆岩主关键层的下沉曲线方程。(2)利用采动覆岩隔离注浆充填对关键层支撑作用的力学模型,分析了注采比和注浆层位对采动覆岩隔离注浆充填作用下关键层下沉的影响。结果表明关键层任一点的下沉值随着注采比的提高而近似呈线性递减趋势;从关键层的下沉与注浆层位的关系来看,注浆层位越高,关键层的下沉越小。(3)利用采动覆岩隔离注浆充填对关键层支撑作用的力学模型,分析了双工作面开采时,隔离煤柱对关键层下沉的影响。本文通过计算认为,对于不同的覆岩条件,所需的隔离煤柱宽度是有变化的,但最终都存在一个最小的能使首采面不受临近工作面开采影响的隔离煤柱宽度。这也表明第一个工作面关键层下沉的增量是由临近工作面开采时隔离煤柱的压缩所造成的。(4)通过数值模拟对理论分析进行了简单的验证,模拟结果表明,采动覆岩隔离注浆充填下,关键层下沉的弹性地基梁理论模型是合理的。
[Abstract]:In recent years, the isolated grouting and filling technology of mining overburden has been successfully applied in the mining of single working face in Huaibei mining area and has achieved a good effect of reducing subsidence. However, when mining adjacent face, it will inevitably cause the increase of overlying strata subsidence in the first working face, but what is the mechanics mechanism of its internal rock movement is not clear. Therefore, this paper abstracts the mechanics model of key layer to analyze this practical problem. Based on the critical layer theory and the elastic foundation beam theory, the theoretical derivation of the mechanical model of the action of mining overburden isolated grouting and filling on the support of the key layer is carried out in this paper. The main research results are as follows: (1) under the support of mining overburden isolated grouting filling body, single, The equation of subsidence curve of the main key strata of overburden in double working face. (2) the mechanical model of supporting the key strata by using mining overburden separate grouting filling, The effects of injection-production ratio and grouting layer on the subsidence of key strata under the action of isolated grouting and filling of mining overburden are analyzed. The results show that the subsidence value at any point of the critical layer decreases linearly with the increase of injection-production ratio. According to the relationship between the subsidence of the key layer and the grouting layer, the higher the grouting layer, the smaller the subsidence of the critical layer. (3) by using the mechanical model of separating grouting filling with mining overburden to support the key layer, the paper analyzes the mining of double face, To isolate the influence of coal pillar on the subsidence of key stratum. In this paper, it is considered that for different overburden conditions, the required width of the isolated coal pillar varies, but there is a minimum width of the isolated pillar which can make the first mining face free from the influence of the mining near the working face. It also shows that the increment of subsidence of the first face key layer is caused by the compression of the isolated pillar when mining near the working face. (4) the theoretical analysis is simply verified by numerical simulation, and the simulation results show that, The theoretical model of elastic foundation beam for subsidence of key strata under isolated grouting filling of mining overburden is reasonable.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD325

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