Seismic analyses of conventional and improved marginal wharves

Marginal wharves are key components in providing functionality of port facilities. Ports are central components of the US economy. Earthquake damage to a port can disrupt the economic stability. Therefore, port facilities must be able to quickly return to full operation shortly after a seismic event. Prior studies have shown that integrity of marginal wharves may be compromised by excessive soil movement and structural damage. The latter is often localized at pile-to-wharf connections and in the pile body buried within the soil. Recent research has resulted in an improved connection design that mitigates damage. This study was undertaken to evaluate the full seismic performance of marginal wharves including both conventional and damage-resisting connections. A series of finite element models of a representative pile-supported wharf facility were created. The models varied in their moment-resisting pile-to-wharf connections. A total-stress analysis approach was used to capture the soil response along with p-y, t-z, and Q-z soil-structure interaction springs. Validated connection interface elements were integrated with non-linear frame elements to simulate the marginal wharf structure and substructure. Non-linear static pushover and dynamic time history analyses, for three different hazard levels, were performed. The results of the numerical simulations were used to assess the performance of the marginal wharf including estimates of crane damage and port downtime.