Assessment of soil-liquefaction potential based on geoelectrical imaging: A case study

Abstract

Due to the low spatial resolution of S-wave velocity ([Formula: see text]) depth profile derivable from multichannel analysis of surface waves (MASW) for soil liquefaction studies, we have developed an alternate novel method for better [Formula: see text] estimation using high-resolution electrical resistivity tomography (ERT) data, which does not require standard penetration test (SPT) boreholes. Our method uses popular regression equations for transforming resistivity (ERT) sections into synthetic SPT-[Formula: see text] data sections. In turn, these are used for getting factor of safety (FOS) sections, whose analysis leads to assessment of soil-liquefaction hazard potential of a field site. The conversion of SPT-[Formula: see text] data into FOS sections involves standard cyclic stress and cyclic resistance ratio computations. Our methodology is illustrated with the help of a field study involving two sites on our IIT Roorkee Campus, India. The acquired data sets include ERT and MASW. The achieved results including two different regression equations indicate that our ERT-based soil liquefaction study is much broader and seems to be more refined than the popular MASW-based one. Our proposed methodology can be refined further if few SPT boreholes are present in the study region. Further, a close scrutiny of FOS sections of our study sites indicates that our study region (IIT Roorkee campus, India) is having soil liquefaction risk for an earthquake magnitude [Formula: see text] 7.5.