Criticality of Angle of Earthquake Shaking on Pounding Behaviour of Buildings

Abstract: Buildings with an insufficient separation gap (Sg) in either direction cause pounding effects between them and suffer damages, partially or entirely, depending on the shaking level. The level of damage increases with the direction of shaking and asymmetry. But code provisions usually place restrictions on separation gaps, considering the adjacent buildings. Hence, it is intended to check the provision's applicability for different directions of shaking, as most of the buildings in rural and urban areas are almost congested. Also, the effect is more prominent in stiff or flexible buildings. Two stiff buildings with 3 and 5 storeys are designed and detailed using IS 456, IS 1893-1, and IS 13920. Elastic and inelastic analyses are conducted (with and without including the effect of masonry walls as equivalent diagonal struts), and the direction of ground motion is varied from 0°, 30°, 45°, and 60°. Based on the maximum inelastic displacement, level of damages in structural elements, damage mechanism obtained from inelastic analyses, and Sg estimated using IS 1893-1, it is evidenced that the Sg specified in code provisions is insufficient. Also, the level of damage increases with the direction of the shaking. It is necessary to revise the separation gap specified in the building code provisions, including a minimum Sg based on limiting drift.