Seismic Liquefaction Hazard and Site Response for Design of Piles in Mumbai City

Mumbai city is the financial capital of India with the highest population density and formed by reclamation of land over time from original seven different islands. As per Indian seismic design code IS 1893-Part 1, Mumbai city is located in Zone III, hence may experience moderate intensity earthquake which may lead to liquefaction of some typical soil sites of Mumbai city. In this paper, using available recent procedures for liquefaction analysis, seismic liquefaction hazard maps for Mumbai city are prepared. Also the typical coastal soft soil strata of Mumbai may be prone to soil amplification for different bed rock earthquake motions and the present study shows that typical ranges of soil amplification factor for bed rock acceleration are 1.2–3.5. Hence, construction of pile foundation, which is mostly used for the effective use of the most precious land of Mumbai city for construction of high rise buildings, need special attention in design when such possibly liquefied soil strata with soil amplification during moderate earthquake intensity is considered. Present study shows the response of pile foundation in both non-liquefied and liquefied soil by considering both kinematic and inertial responses in terms of displacement and bending moments of piles, which are necessary to consider for seismic design of pile foundation in typical Mumbai soil. © 2014, Indian Geotechnical Society.