Behavior of vertically irregular structures near mines: Comparison of responses under seismic and mine blast-induced ground motion

Due to architectural and functional considerations, buildings with irregular configurations are frequently constructed with rapid urbanization. During a seismic or blast activity, the performance of a building depends on various factors like adequate lateral strength, stiffness, ductility, regularity, and the extent of simplicity in the configuration. The irregular distributions of the stiffness, mass, and strength in the plan and height of the building create irregularity within the structures. The purpose of this study is to understand the nature of response under seismic ground motion and that obtained from ground vibration generated due to mine blasts if such buildings are situated near mines. This study also emphasizes on identifying the critical location of stress concentration of the structures under both seismic and mine blast-induced ground motion. Base shear, fundamental natural periods, mode shapes, and member forces for a few buildings with typical irregular configurations and similar buildings with regular counterparts are obtained. Nonlinear dynamic analysis has been carried out on irregular buildings for confirming the trends in behavior observed from linear dynamic analysis. Since the mine blasts take place sequentially, the study also aims to prescribe a suitable delay interval between such series blasts to minimize the vulnerability of vertically irregular seismic structures to the possible extent.