Spatial Liquefaction Analysis System

Assessment of liquefaction potential index for Mumbai city

“…LPI is computed by taking integration of one minus the liquefaction factors of safety along the entire depth of soil column limited to the depths ranging from 0 to 20 m below the ground surface at a specific location. The level of liquefaction severity with respect to LPI as per Iwasaki et al (1982), Luna and Frost (1998), and MERM (2003) is given in Table 1. The factors of safety against liquefaction (FS) and the corresponding liquefaction potential index (LPI) are determined by comparing the seismic demand expressed in terms of cyclic stress ratio (CSR) to the capacity of liquefaction resistance of the soil expressed in terms of cyclic resistance ratio (CRR).…”

“…Factors of safety (FS) at different depths of the soil profiles are computed for the earthquakes of magnitude M w = 6.0, M w = 6.5, and M w = 7.0 with a max value of 0.3 g. Figure 4 shows the soil profile, corrected N values, fines content, and FS values against liquefaction along the depth. LPI at this particular site is calculated from FS values based on the expressions by Luna and Frost (1998). LPI values are computed at the typical site for magnitudes of M w = 6.0, M w = 6.5, and M w = 7.0, with a max 0.3 g, and the results are presented in Tables 3 through 5.…”

“…The liquefaction potential index (LPI) quantifies the severity of liquefaction and predicts surface manifestations of liquefaction, liquefaction damage or failure potential of a liquefaction-prone area (Luna and Frost, 1998). LPI is computed by taking integration of one minus the liquefaction factors of safety along the entire depth of soil column limited to the depths ranging from 0 to 20 m below the ground surface at a specific location.…”

“…For the soil profiles with the depth less than 20 m, LPI is calculated using the following expression (Luna and Frost 1998):…”

“…Iwasaki et al (1978) proposed liquefaction potential index (LPI) to overcome this limitation of FS. Liquefaction potential index (LPI) provides an integration of liquefaction potential over the depth of a soil profile and predicts the performance of the whole soil column as opposed to a single soil layer at particular depth and depends on the magnitude of the peak horizontal ground acceleration (Luna and Frost, 1998). LPI combines depth, thickness, and factor of safety against liquefaction (FS) of soil layers and predicts the potential of liquefaction to cause damage at the surface level at the site of interest.…”