煤与瓦斯突出物理模拟相似准则建立与分析

Establishment and analysis of similarity criteria for physical simulation of coal and gas outburst

相似准则是物理模拟的理论依据,是研发相似材料确定试验条件的基本前提。煤与瓦斯突出物理模拟相似准则是制约模拟试验发展的瓶颈。针对描述煤与瓦斯突出全过程的力学模型尚未建立的现状,尝试采用描述突出孕育阶段的气固耦合模型进行相似准则推导。基于气固耦合方程,采用相似变换法推导了相似准数。该组相似准数可保证煤岩变形破坏规律相似,却难以发生突出现象。提出了采用能量模型推导煤与瓦斯突出相似准则的思路。改进了前人的能量方程,经过相似变换导出了新的相似准数。该组相似准数可保证试验模型与原型能量集聚、转移和释放规律相似。结合两组相似准数,在保证能量模型相似的基础上,考虑煤岩变形破坏规律相似,确定了煤与瓦斯突出物理模拟相似准则。与前人的物理模拟试验结果进行对照,验证了相似准则的合理性。

Similarity criteria is the theoretical basis of physical simulation. It is the premise for developing similar materials and determining the condition of experiment. Similarity criteria limits the development of physical simulation test of coal and gas outburst. Because the mechanical model of whole coal and gas outburst process has not been established,the similarity criterion was established using the gas-solid coupling model which could describe the embryonic stage. Similarity criterion above can ensure the deformation and failure law is similar. However,it cannot guarantee the coal and gas outburst phenomenon. This paper presented a method to derive the similarity criteria based on the energy model. A new similarity criterion was derived by similarity transformation. It can ensure that the perimental model is similar to the prototype in energy concentration,transfer and release. Combined the two groups of similarity criterion,on the basis of the similarity of the energy model and coal deformation and failure,a new similarity criteria of physical simulation on coal and gas outburst was established. Compared with the previous physical simulation results,it isproved that the similarity criterion is reasonable.