Probabilistic Liquefaction Potential Approach for Colombo Port City

The Colombo Port City, Sri Lanka's major coastal project, has been constructed by transforming 269 hectares of sea into a vibrant residential, retail, and business land area using 65 million cubic meters of dredged sand. Coastal areas undergoing land reclamation often face challenges related to liquefaction, primarily induced by natural seismic events. Recent studies underscore the importance of considering seismic events during the design phase of construction projects in Sri Lanka. This paper describes a study that performed probabilistic liquefaction hazard analyses using a well-established method. To investigate surface damage potential, the Liquefaction Potential Index method was employed. Detailed analysis of the results was used to develop maps illustrating liquefaction behaviour with depth, providing a comprehensive assessment of the potential for ground liquefaction. The comparison of the two methods indicates that, out of the four earthquake combinations considered, two scenarios are particularly critical. Additionally, certain land plots have been identified as more vulnerable to liquefaction.