Assessment of liquefaction potential index for Mumbai city

Abstract

Mumbai city is the financial capital of India and is fifth most densely populated city in the world. Seismic soil liquefaction is evaluated for Mumbai city in terms of the factors of safety against liquefaction (FS) along the depths of soil profiles for different earthquakes with 2% probability of exceedance in 50 yr using standard penetration test (SPT)-based simplified empirical procedure. This liquefaction potential is evaluated at 142 representative sites in the city using the borehole records from standard penetration tests. Liquefaction potential index (LPI) is evaluated at each borehole location from the obtained factors of safety (FS) to predict the potential of liquefaction to cause damage at the surface level at the site of interest. Spatial distribution of soil liquefaction potential is presented in the form of contour maps of LPI values. As the majority of the sites in the city are of reclaimed land, the vulnerability of liquefaction is observed to be very high at many places.