Assessment of Seismic Liquefaction of Soil Site at Mundra Port, India, Using CPT and DMT Field Tests

Cyclic soil liquefaction in the past has resulted in severe damage to structures and lifeline services. Mostly, standard penetration test and cone penetration test (CPT) are used for evaluation of liquefaction; however, the dilatometer test (DMT) is better suitable due to its ability to detect soil stress history and aging. This study aims to compare the DMT-based cyclic resistance ratio (CRR) correlations available in the literature with well-established CPT-based CRR correlation at a site in Mundra, Gujarat, that had moderately liquefied in 2001 during the Bhuj earthquake. The available earthquake history is scaled using attenuation relationship for Peninsular India, and the peak ground acceleration is assessed by ground response analysis using the CPT data. The factor of safety (FSL) against liquefaction is evaluated using field data obtained from CPT and DMT. Also, Liquefaction Potential Index (LPI), settlement (S) and Liquefaction Severity Number (LSN) are evaluated to determine the consequence of liquefaction, and the performance of the foundations supported on liquefied soil. The results verify the liquefaction damage observed in 2001 during the Bhuj earthquake and indicate that the site possesses a moderate risk of liquefaction. It shows that the site is susceptible to minor to moderate consequences of liquefaction, such as sand boils and small damage to existing structures. It also indicates that the CPT-based CRR correlation is conservative compared to DMT-based CRR correlation and warrants the use of independent DMT-based CRR correlations or use of at least two methods to assess liquefaction at critical sites. © 2019, Indian Geotechnical Society