Numerical analysis of explosion to deflagration process due to methane gas explosion in underground structures

This paper is a study mainly aimed to understanding of deflagration and explosion characteristics of methane gas system explosion in a tunnel structures. Underground infrastructure structures are threatened by aftermaths due the all hazards: natural, criminal, terrorist, and accidental such as a gas detonations, bumps, terrorist attacks, etc. Human victims, decreasing of bearing capacity of the structural system and long-lasting traffic troubles can be very extensive. This is why it is of great importance to assess dynamic impacts of explosives, which are required by some contractors or developers for lowering the danger of damage of structures. In order to fulfil these demands accurate computation is necessary and on the other hand also new protective structures and methods have to be suggested and verified. The expensive, time consuming or even dangerous experiments should be proved by the numerical methods. A series of tests was conducted to investigate the blast evaluation of premixed methane-air burning and explosion in the underground tunnel. LVDT and pressure transducers were used to record deflection histories and measured air blast pressure histories. The full-scale experimental study was performed by the Scientific-Research Coal Institute VVUU in Ostrava under the supervision of the Department of Technology of Building, Czech Technical University in Prague. The analysis of the tunnel structure caused by a blast load is presented in this paper based on the time-dependent measurements of the response of the underground structures to the blast wave loads that were successfully recorded using a variety of measurement devices.