Improved Predictive Methods for Airblast Shielding by Barrier Walls

Abstract

Urban planners often consider the use of barrier walls as a means of protecting structures and other assets from terrorist vehicle bombs. Barrier walls offer a means of halting the approach of vehicle bombs, thereby limiting the proximity of the bomb to the at-risk asset. Depending upon their height and structural integrity, barrier walls may also provide significant shielding from the airblast produced by the bomb. Several methods exist for the prediction of this shielding effect. Unfortunately, these methods tend to be rather inaccurate, due primarily to the complexity of the airblast/barrier wall interaction, and to the lack of a comprehensive database upon which to form a predictive methodology. During the past four years, the US Army Engineer Research and Development Center has conducted an extensive series of small-scale experiments and hydrocode calculations to examine barrier wall shielding of structures. This database is now being used to develop an improved methodology to predict peak reflected pressure and impulse behind barrier walls of various heights for a wide range of explosive-to-wall and wall-to-structure distances. A wide range of target heights on the shielded structure are also addressed. This paper provides an overview of the experimental and computational database, and the new predictive methodology now under development.