Gas emission from the working face in a gas-bearing coal seam impairs safe production. Especially in the coal face, influenced by mining, pressure-relief gas in adjacent seams flows into the working face through the goaf. Moreover, caved overlying strata in different regions show differences in pore and seepage characteristics. Thus, the caving of overlying strata in the goaf of a working face was explored by carrying out physical similarity simulation. Then, based on the characteristics of the geometric shapes of caved overlying strata after mining, a trapezoidal three-dimensional model for gas extraction was established. According to the calculation result, the parameters of field high-level boreholes were optimized. Then, the controllability of gas concentration at the working face after gas extraction was assessed by applying statistical process control. The result showed that after the observed surface of the physical similarity model was lightened, it was more favorable for conducting the test. Moreover, the maximum gas concentration in the goaf was negatively correlated with the diameter of high-level boreholes and the negative pressure for gas extraction. A statistical process control chart revealed that the gas concentrations at the working face were safe after gas extraction based on high-level boreholes, which also validated the feasibility and effectiveness of the model.

含瓦斯煤层中工作面的瓦斯涌出会损害安全生产。特别是在采煤工作面中，受开采影响，相邻煤层中的卸压气通过采空区流入工作面。此外，不同区域的塌陷覆岩地层在孔隙和渗流特征方面存在差异。因此，通过进行物理相似性模拟，研究了工作面采空区上覆岩层的崩落。然后，根据开采后塌陷上覆地层的几何形状特征，建立了梯形三维瓦斯抽采模型。根据计算结果，对现场高位井眼的参数进行了优化。然后，通过采用统计过程控制来评估抽气后工作面气体浓度的可控性。结果表明，将物理相似性模型的观察表面减薄后，更有利于进行测试。此外，采空区的最大瓦斯浓度与高位井眼的直径和瓦斯抽出的负压呈负相关。统计过程控制图显示，在基于高位钻孔的瓦斯抽采后，工作面上的瓦斯浓度是安全的，这也验证了该模型的可行性和有效性。采空区的最大瓦斯浓度与高位井眼的直径和瓦斯抽采负压呈负相关。统计过程控制图显示，在基于高位钻孔的瓦斯抽采后，工作面上的瓦斯浓度是安全的，这也验证了该模型的可行性和有效性。采空区的最大瓦斯浓度与高位井眼的直径和瓦斯抽采负压呈负相关。统计过程控制图显示，在基于高位钻孔的瓦斯抽采后，工作面上的瓦斯浓度是安全的，这也验证了该模型的可行性和有效性。