Liquefaction potential study based on integrated geoelectrical imaging and geotechnical data - A case study

Abstract

Soil liquefaction potential through low-resolution shear wave velocity (Vs) information derived from Multi-channel analysis of shear waves (MASW) and Standard Penetration Test (SPT) results of geotechnical engineering is a standard procedure. But such an estimate is crude at shallow depths. So, we propose an alternate refined method based on combined use of Electrical Resistivity Tomography (ERT) and SPT 'N'. We provide a case study involving two sites to illustrate the effectiveness of our method. Initially, we compute shear wave velocity (Vs) from resistivity data and SPT 'N' value through established regression equations. Then, we make use of familiar relations based upon corrected (N160) values and intensity of cyclic loading to compute factor of safety (FS) to assess soil liquefaction of a site. Our results transform observed ERT prifile sections into FS sections and they clearly stress that study region (IIT Roorkee campus, India) is having minimal soil liquefaction hazard for an earthquake magnitude Mw 7.5.