Generation of a pressure–impulse diagram for a temporary soil wall using an analytical rigid-body rotation model

Abstract

This study aimed to provide a simple and efficient model to calculate a time history of response and construct a pressure–impulse ( P–I) iso-damage curve for a free-standing soil-filled HESCO Bastion (HB) concertainer ® wall subjected to blast loading based on the maximum rotation of the wall. An analytical model is formulated for a free-standing HB simple straight wall based on rigid-body rotation. The maximum rotations observed in a full-scale blast testing of free-standing simple straight walls were compared with the maximum rotations calculated using the proposed analytical model and are in good agreement. The model is subsequently used to calculate a P–I curve for the wall, which is a common iso-damage curve used in a blast-resistant design, and represents various combinations of blast pressures and impulses required to damage the wall to a selected failure criterion. The failure criterion was selected as the critical amount of rotation required to completely overturn the wall. The resulting P–I curve was plotted along with the different charge performance curves or the pressures and impulses of different charge sizes. The curves show that the overturning of the HB walls, except for extremely large charge sizes, is governed by the amount of blast impulse and not the blast peak pressures. This indicates that the response of HB walls is impulse dominated. The effect that material density has on P–I curves was studied and found to be relatively insignificant. The P–I curves calculated based on different degrees of rotation as failure criteria were also plotted and compared. The curves showed that the required blast impulse to rotate the wall to 75% of the complete overturning angle and the required blast impulse to completely overturn the wall were very close. This illustrates that the magnitude of rotation becomes increasingly sensitive to blast impulse as blast impulse approaches the critical blast impulse required to completely overturn the wall.