Numerical Investigations of a Novel Offshore Platform Blast Wall Design Using Energy Absorption Devices at Supports

Abstract Offshore blast walls are critical safety barriers designed to protect personnel and equipment from hydrocarbon explosions. Traditional designs often struggle to simultaneously satisfy code requirements for deflection limits and weld integrity under high-intensity blasts. This study proposes a novel offshore blast wall concept incorporating energy-absorbing support devices comprising PMI foam-filled sliding cores and rotational springs. The devices provide flexible support with adjustable translational and rotational stiffness, enabling controlled energy dissipation through foam crushing and spring mechanisms. Finite element analyses were performed to compare the proposed design with traditional Type 1 and Type 2 configurations under strength-level (SLB, 1 bar) and ductility-level (DLB, 3 bar) blast events. Parametric studies further investigated the influences of translational stiffness in the foam elastic range (Kt1), hardening stiffness (Kt2), rotational stiffness (Kr), and blast duration. Results demonstrate that the proposed design significantly outperforms traditional schemes: under SLB, it exhibits negligible plastic deformation (~1 mm vs. 7 mm and 4 mm for traditional designs); under DLB, it limits panel deflection to 167.7 mm (44% reduction) while maintaining support plastic strains at 4.54% (below the 5% rupture limit), whereas traditional designs fail both criteria (303.3 mm deflection and 26.68% PEEQ). Parametric findings reveal that Kt1 and Kr critically influence deflection and strain responses, while Kt2 affects the safety margin against densification. Long-duration blasts are identified as more onerous due to td/Tn ratios. The proposed design offers a balanced solution for enhanced blast wall resilience in offshore applications.