Characteristic Study on Gas Blast Loadings in an Urban Utility Tunnel

Abstract

China is actively building urban utility tunnels and incorporating gas pipes into the tunnels. However, there is a certain risk of leakage and explosion when gas enters the tunnels. If the gas pipe leaks and causes an explosion, this will not only seriously damage the integrated tunnel structure and other pipelines, but also lead to a catastrophic impact on the surrounding buildings. It is therefore necessary to study the safety of urban utility tunnels under gas blast loadings. In the present work, based on a completed gas explosion model, we investigated the blast loading characteristics of a typical utility tunnel to achieve the shock wave propagation law and distributions of the explosion. We also analyzed the effects of gas concentration, pressure relief vent, and gas volume on the shock wave load. By dimensional theoretical analysis, we established a formula for calculating the overpressure peak and impulse for such utility tunnels. The research can therefore provide loading information for the safety assessment and further improve the antiexplosion safety performance of utility tunnels.