Earthquake Behaviour of Stilt Buildings on Hill Slopes

Buildings are built in hilly terrain due to scarcity of land and increased populations. Mostly, buildings are raised above ground on slopes using stilts of different heights to attain a uniform floor level. Thus, the buildings become an open ground storey on hill slopes. Such buildings are primarily located in earthquake-prone regions and have sustained huge damage or collapsed from past earthquakes. Building code provisions do not provide specific guidelines for designing such buildings except limiting the storey height when estimating the natural period. Therefore, a set of building configurations located in plain terrain and hilly regions is used to demonstrate the vulnerability of stilt buildings on slopes. The buildings are designed and detailed using IS 456, IS 1893–1, and IS 13920. The effect of masonry infill walls is accounted for, like an equivalent strut. The inelastic behaviour of these buildings is studied using nonlinear static analysis, considering the maximum considered earthquake (MCE). The design recommendations are proposed for the building code provisions using the maximum inelastic drift at the performance point, capacity curve, damage mechanism, and level of damage in structural elements.