二氧化碳相变致裂软岩实验研究

Experimental Study on Fracture of Soft Rock Fracturing by Phase Change of Carbon Dioxide

为了研究二氧化碳相变产生的高压气体动态破岩的机理,通过建立设有分布式光纤传感器的物理模型结合数值模型的方法,研究了二氧化碳相变致裂煤体的内部效应,得到了二氧化碳相变高压气体动压破岩的机理及岩体裂隙、强度和二氧化碳相变气体压力等参数之间的关系。研究表明:气体准静压破坏煤体主要集中在煤体强度薄弱的区域,且气体压力要高于煤体破坏的最低极限值;原生裂隙会改变二氧化碳相变致裂煤体的空间范围和煤体的破坏程度,原生裂隙与炮孔之间的夹角越小、距离越近,越明显。

In order to study the mechanism of dynamic rock breaking by high pressure gas generated by carbon dio-xide phase transition, internal effect of carbon dioxide phase change cracking in coal was studied by establishing a physical model with distributed optical fiber sensing and numerical model. The mechanism of high-pressure gas dynamic pressure rock breaking and the relationship between rock mass fissure, strength and gas pressure of carbon dioxide phase change were obtained. Results show that gas pressure damaged coal is mainly concentrated in the area where the strength of the coal is weak, and the gas pressure is higher than the minimum limit of coal body damage. Primary crack will change the spatial extent of the coal body and the degree of damage of the coal body. The smaller the angle between the crack and the blast hole is and the closer the distance is, the more obvious it is.