TOWARDS UNDERSTANDING THE BUNCEFIELD EXPLOSION THROUGH ADVANCED NUMERICAL ANALYSIS AND EXPERIMENTAL INVESTIGATIONS

摘要

The paper reports on two series of studies carried out to understand the Buncefield explosions (Explosion Mechanism Advisory Group, 2007; HSE, 2009). The first series of studies were carried out to aid understanding of the severe damages which indicated the possibility of explosion overpressures well above those in an open turbulent deflagration. These involved numerically simulating the detonation of pancake shaped clouds using similar settings and configurations as those experimentally tested by Fishburn (1981). Reasonably good agreement is achieved on the predicted overpressure and drag impulse for the three monitoring points in the tests. Further analysis of the predictions have illustrated important salient features of such pancake cloud detonations which are in line with some forensic evidence of the incident. The second series of studies involve experimental and finite element (FE) analysis of lightweight metal boxes, similar to the lightweight steel junction boxes on the site located within the area covered by the gas cloud at Buncefield. These boxes were tested under a range of different loading conditions using hydrostatic pressure, gas explosions and high explosive charges during the Phase I research. Measurements were conducted for the residual plastic deformations of these boxes. A FE modelling approach was developed and validated with these measurements and the recorded pressure-time history during the tests. The results have been used to produce iso-deformation lines which can be used to aid accident investigations by back tracking the blast loading from structure deformation.