Dynamic Response of Bowstring-arch Highway Bridge Subjected to Above and Below Deck Close-range Large Explosion

¹ Department of Civil Engineering, Jamia Millia Islamia (A Central University), 110025 New Delhi, India
² Department of Civil Engineering, Netaji Subhas University of Technology, 110073 New Delhi, India

^* Corresponding author: akramshahbaz26@gmail.com

Abstract

Explosion incidents that are unforeseen can lead to the occurrence of extreme loads, resulting in the generation of remarkably high stress levels within the materials comprising various structures. This can cause significant damage to crucial elements and potentially trigger a disproportionate collapse or even initiate a progressive collapse. Bridge structures, which serve as vital lifelines for cosmopolitan areas and strategic bordering environments, hold immense economic and political significance. The failure of these structures can have severe consequences with far-reaching implications. The use of a steel bowstring-arch bridge is a practical choice for congested crossings and remote border areas where spans are short. However, the current design codes for bridges do not take into account high-strain loadings such as blasts or impacts, nor do they provide recommendations for preventing these occurrences during construction or throughout the lifespan of the bridge. Explosive incidents cause greater damage in terms of material damage and loss compared to earthquakes. There has been limited investigation into how steel-concrete bridges respond to explosions in the past. This study examines the numerical analysis of a bowstring-arch highway girder bridge made of steel and concrete. The bridge is supported at both ends and is subjected to close-range concentric explosions above and below the deck at the center and end of the bridge. To model the bridge and predict its behavior, the authors utilized the Abaqus software suite. For the analysis, a significant quantity of TNT weighing 1.63-tonne has been positioned at the midpoint of the bridge and is defined using the Eulerian-Lagrangian scheme. The transmission of the explosive shockwaves within the bridge material under the given loading circumstances is illustrated and elucidated. The behavior of the bridge is examined in relation to plastic deformations, primary stress, displacement, size of the crater, and overall energy of damage.