Performance of masonry heritage building under air-blast pressure without and with ground shock

ABSTRACT In general, the blast-induced ground shock excites the foundation of the structure prior to the air-blast pressure because of the obvious reasons of difference in wave propagation velocities. However, the ground shock and air-blast pressure might act simultaneously on the structure for some standoff distance with a particular quantity of the explosive charge and cause severe damage than by air-blast pressure. Therefore, the ground shock and air-blast pressure both should be considered for estimating the structural response by such a near-field detonation. The objective of the present study is to assess the performance of the masonry heritage building under air-blast pressure without and with ground shock generated from on the ground spherical-shaped TNT explosive charge at varying standoff distances. The considered building is a heritage brick masonry structure in lime-surkhi mortar. The time lag between the ground shock and air-blast pressure for different scaled distances is evaluated. Stresses have been computed and are compared with the provisions of the Indian and Australian Standard Codes of Practice for Structural Use of Unreinforced Masonry. Also, the damage assessment has been carried out using the concrete-damaged plasticity (CDP) model available in the ABAQUS finite element program.