Investigation and Analysis on the Explosion Accident in the Mountain Tunnel

Abstract

Blasting operation has gradually become an efficient and fast construction method with the rapid development of industrial level. In China, hole drilling smooth blasting method has been widely used in most railway tunnel projects. Therefore, substantial attention should be paid to the safety of tunnel blasting. In order to show the properties of explosive products in limited tunnel spaces and their influence on people, the overpressure damage of shock wave and the effects of heat radiation and harmful gas from explosion were checked by performing theoretical analysis and numerical simulation. This study took the sudden explosive explosion in a tunnel excavation as an example. The accuracy of the calculation and analysis results were verified by on-site investigation. The main cause of the accident and related preventive measures were also discussed. The dangerous range of casualties under different explosive charges in the tunnel was finally achieved by relating the theoretical analysis to the actual circumstance. Results show that the explosion of a large number of detonating fuses in the semi-closed tunnel is equal to the explosion of approximately 200 kg of TNT. The produced shock wave, thermal radiation, and harmful gas affect the scope of over 400 m with enormous destruction. The explosive power of a detonator cord should never be underestimated. The large number of casualties in this tunnel explosion accident highlights the importance of safety. This study provides specific reference for determining safety range in a blasting construction, which would also provide great guidance in other tunnel projects.