地下爆炸气体输运的一种双孔隙度数学模型

A dual porosity mathematical model of gas transportation on underground detonation

考虑气体在压力驱动下的渗透、气体和岩体的热传导以及气体的扩散，建立了用于模拟地下爆炸气体输运的二维轴对称双孔隙度双渗透率数学模型，并编制了数值模拟程序；研究了参数在取值范围内变化对计算结果的影响。结果显示：泄漏到地表的气体随着裂隙区域圆心角的增大而先增大后减小，随裂隙渗透率的增大而增大，随介质孔隙度和孔隙渗透率的增大而减小。用该模型对一次砂砾岩中地下爆炸实验气体的泄漏行为进行了数值模拟。将数值模拟结果与气体泄漏实测结果进行对比，反推出当地介质的裂隙渗透率在4×10^-11 m2～5×10^-11 m2之间。利用反推得到的介质参数，可以对同类介质中地下爆炸气体泄漏行为进行预测。

A two dimensional cylindrical symmetrical mathematical model of dual porosity and dual permeability is built by taking into account of gas permeation in porous media,gas diffusion and heat conduction between gas and wall rock.A corresponding simulation code is compiled.By comparing the influences of different parameter values on simulation results,the following conclusions can be drawn: The portion of gas leakage on the earth surface firstly increases then decreases with the central angle of the fissure zone increases.The portion of gas leakage increases with permeability of fissure zone increases,and decreases with porosity and permeability of porous medium increases.An example of gas leakage behavior of underground explosion experiment in sandy gravel is simulated by using the compiled code and the permeability of fissure zone is deduced to be from 4×10-11m2 to 5×10-11m2 by contrasting numerical simulation results with experimental ones.The gas leakage behavior of underground detonation in the same kind of media could be predicted by the model and deduced parameters.