# Failure Mode Analysis and Dynamic Response of a Coal Mine Refuge Chamber with a Gas Explosion
## 1 Introduction  
A gas and coal dust explosion is a potential hazard in the majority of coal mines. Through the analysis of accident cases, the number of coal miners that are instantly killed in a fire and explosion accident is only a small fraction of the total number of accident casualties. Miners do not have enough time to evacuate after accidents due to many kinds of risk, high-temperature smoke, or high concentrations toxic gases, and so on [1]. The Mine Safety and Health Administration (MSHA) looked at a coal mine accident survey from 1900 to 2006. The survey showed that the success rate of rescues could be increased over 50% by applying safety facilities such as a refuge chamber [2]. There have been many successful refuge chamber application cases in the world. For instance, in a Saskatchewan fire accident in 2006, 72 trapped miners moved to a refuge chamber and were rescued after 26 h. In August 2010, when Chile's San Jose copper and gold mine collapsed, 33 miners were trapped underground for 69 days and rescued from a refuge chamber [3]. Thus, it has great significance for the safety of miners to set up a mine refuge system in coal mine. For now, many countries such as the United States, Britain, Germany, Australia, and South Africa are promoting the application of refuge chambers, actively [4]. Considering the complexity and specificity of the nature of mine disasters, many countries have a high demand for the ability of refuge chambers to resist all kinds of disasters, such as explosions andfires. The design standard for refuge chambers put forward by MSHA stipulates that the cabin should be able to resist 15 Psi (about 0.1 MPa) overpressure [5] in order to ensure that the refuge chamber would not be damaged under a gas explosion or mine fire and other accidents. The research on coal mine refuge chambers in China is relatively late. Relevant standards are still under development. In recent years, the poor safety situation of coal mines have led to the rapid development of the study in refuge chambers. Recently, the research on refuge chamber anti-explosion performance by means of explosive tests, combined with numerical simulation, has made many achievements. In the last century, some developed countries have established experimental mines for gas/dust explosion tests to study the propagation laws of gas and coal dust explosion flame and the evolution trend of overpressure. In 1982, the Chongqing Branch of the Coal Science Research Institute built China's first gas and coal dust explosion experimental mine tunnel. The total length of the tunnel is 896 m, and the length of test area is 740 m. The cross-section of the experimental mine tunnel is similar to the actual tunnel. The experimental mine tunnel can be used to simulate real mine gas explosion shockwave propagation process and many achievements have been obtained by experiments conducted in this mine tunnel [6; 7]. However, it is not suitable for wide applications because of the limit of space and cost. Compared with experimental research, numerical simulation methods have some advantages, including reducing costs, improving efficiency, and facilitating parameters analysis. [PERSON] _et al._[8] simulated and analyzed air pressure distribution in the refuge chamber. [PERSON] _et al._[9; 10] simulated and analyzed the safety of a refuge chamber in a gas explosion. [PERSON] _et al._[11] preliminarily studied the integrated protective performance of a refuge chamber test platform. [PERSON] _et al._[12] simulated and analyzed the anti-explosion performance of different types of refuge chambers. Chinese scholars simulated and analyzed regularity of the stress and strain and structure optimization of a refuge chamber structure in a gas explosion with the finite element method [13; 14; 15; 16; 17]. Though a lot of refuge chambers had been numerically simulated to reach safety design requirements, they were locally damaged or totally damaged during gas explosion tests in the large scale underground test tunnel of Chongqing Refuge Chamber Test Center.