Towards a model to predict blast propagation around a hemicylindrical barrier

Abstract

Understanding the effects of blast generated by an accidental or a terroristic explosion nearby a critical structure is a main concern for the French Institute for Nuclear Safety (IRSN) and the French-German Research Institute of Saint Louis (ISL). Full-scale reactive phenomena are however seldomly compatible with long-term studies due to cost and regulation issues. Reduced scaled experimental work consequently represents an attractive alternative. Using small plastic explosive charges, blast effects in free-field or around various obstacles based on reference structures can be repeatedly examined, in order to provide the data necessary to develop simplified and numerical models. Following previous work on this topic by IRSN using a blast table and 42 g Hexomax® charges placed on its surface, ISL modified one existing blast pad to reproduce the same configuration at a double scale (333 g charges of Hexomax®). This study was conducted using a reference hemicylindrical obstacle, commonly encountered on industrial sites and also representative of certain transport containers. Numerous pressure sensors installed within the table or the pad thickness and on the surface of the hemicylinders provided the overpressure evolution for different values of the charge to obstacle distance. Explosive charges were ignited at distances up to 3.5 m/kg1/3 from the obstacle at ISL scale to extend the applicability domain of the model described in our previous document (Trélat et al. [18]) at a larger scale. The objective of this work is to assess not only blast effects on a potential target but also its capability to modify the blast propagation in its downstream space.