浅埋煤层开采地表下沉影响因素分析

Analysis on Influence Factors of Surface Subsidence in Shallow Coal Seam Mining

为了研究浅埋煤层开采条件下基岩厚度、松散层厚度及开采厚度3个因素对地表最大下沉值的影响,借助FLAC 3D软件进行数值模拟并运用正交实验法对3个因素进行影响程度排序,得到各因素对地表最大下沉值影响程度排序为:基岩厚度H>松散层厚度h>开采厚度m。通过改变3个因素变量取值,分析三者对地表最大下沉值的影响变化情况。基于数值模拟结果,回归分析拟合得到地表最大下沉值与3个因素的综合函数表达式,通过工程实例对该表达式予以验证,结果表明综合函数表达式具有较高的可信度,可为类似条件下煤层开采地表移动变形预计提供参考。

In order to study the influence of bedrock thickness,unconsolidated layer thickness and mining thickness on the maximum subsidence value of the surface under the condition of shallow coal seam mining,numerical simulation was carried out by using FLAC 3D software,and the degree of influence of the three factors was ranked by orthogonal experiment method,which can be classified as bedrock thickness>unconsolidated layer thickness>mining thickness.By changing the value of three variables,the influence of the three on the maximum subsidence value of the surface was analyzed.Based on the results of numerical simulation,regression analysis was used to fit the comprehensive function expression of the maximum subsidence value and the three factors.The expression was verified by an engineering example.The results show that the comprehensive function expression has high reliability,which can provide a reference for the prediction of surface movement and deformation under similar conditions.