Blast effect from unconfined vapour cloud explosions

Roberts, A.F. and Pritchard, D.K., 1982. Blast effect from unconfined vapour cloud explosions. Journal of Occupational Accidents, 3: 231-247.Despite a considerable effort to predict the consequences of an unconfined vapour cloud explosion (UVCE) at a petro-chemical site, the major source of data remains the actual accidents themselves.The most has not always been made of this diagnostic information and, as an example of the type of work that can be undertaken, an analysis of the blast damage to lamp posts at Flixborough is presented in this paper combined with information from damage to other structures. This analysis provided an insight into the sequence of events. It was concluded from the calculated impulses and estimates of peak overpressures that the overpressure--time history in the near field of an UVCE is very different from that generated by the detonation of a solid explosive. The analysis is also of value in its own right since the estimated loadings can be used as a design basis for geometrically similar structures.A programme to investigate the effect of UVCE type blast waves on simple structures has been started at Buxton, as an aid to accident investigation. The facilities available for this work are described in this paper and the work planned is briefly outlined.