عنوان مقاله [English]
نویسنده [English]چکیده [English]
If layout of underground storage of energetic materials such as explosives, gases and petroleum is designed inappropriately, an unexpected explosion can result in transmission and spread of the explosion to other adjacent underground spaces and cause catastrophic events both in surface and underground. In this paper, a calibrated elasto-plastic numerical model in FLAC3D software is used to simulate the underground storage explosion. The peak particle velocity (PPV) damage criterion and the plastic deformation criterion have been adopted to study the extent of damage zone around the explosion. The results show that the extent of damage measured based on the PPV criterion is larger than the plastic deformation criterion. Investigating responses of concrete lining supports shows tensile ruptures in the concrete due to reflection of stress waves from inner walls, which can cause transmission of explosion without direct contact of damage zone to the nearby storage chambers. Finally, in this paper, the safe separation distance and embedment depth are proposed for three underground storage chambers of explosives in Bakhtiari dam project.
The main purpose of this research is to use numerical modeling in order to predict safe separation distance and embedment depth for underground storage chambers of energetic materials to prevent transmission of explosion between chambers.
Methodology and Approaches
In this paper, major features of underground storage chambers and surrounding rock mass have been numerically simulated using three dimensional (3D) finite difference method. The damage extension around the exploded chamber is evaluated using two criteria of critical PPV and Mohr-Coulomb failure criterion. The results of numerical simulations have been compared with international standards.
Results and Conclusions
The results have proved that due to explosion stress waves reflection from inner walls of adjacent chambers that causes tensional cracks in concrete supports and adjacent rock mass, it is necessary to simulate the presence of adjacent chambers in the numerical models. Results of simulations in different rock masses show that the extension of the damage zone in strong rock masses is lower than that in weak rocks; however, the energy of stress waves propagating within strong rock masses, due to lower attenuating ability of the strong rock masses, is high and vice versa.