Analysis of the structural response of Beirut port concrete silos under blast loading

Several months after August 4, 2020, Lebanon is still recovering from the enormous explosion at the port of Beirut that killed more than 200 people and injured more than 7500. This explosion ripped the city to shreds and significantly damaged the Beirut port silos. Saint Joseph University of Beirut “the school of engineering ESIB” in collaboration with “Amann” Engineering performed a 3D scan of the Beirut port silos to assess the silos’ level of damage. The obtained data was then compared to the numerical modelling results, obtained from Abaqus explicit, in order to estimate the blast magnitude and to check if the pile foundation can be reused in building new silos at the same place due to the limited space available at the port of Beirut while considering the soil-foundation-structure interaction effect. In addition, the silos’ structural response against the filling of the silos at the time of explosion was investigated. The displacement of the silos and the amount of silos’ damage obtained from the fixed and flexible numerical models indicate that a blast magnitude of 0.44 kt TNT (approximately 1100 tons of Ammonium Nitrate) best estimates the 20 to 30 cm silos’ tilting in the direction of the blast. In addition, the soil and the foundation played a positive role by absorbing part while dissipating less amount of the blast energy. Also, the grains at the time of the event did not affect the silos’ deformation and damage amount. Noting that the displacement of the pile foundation exceeded all limits set by design codes, indicating that the pile foundation cannot be reused to build new silos at the same place