Navigating Existing Building Codes for Seismic Upgrade of Marine Structures Supporting Buildings

Marine structures and buildings are designed with different codes and methodologies. When marine structures support buildings, the engineering team must navigate these codes and propose an approach to the Authority Having Jurisdiction (AHJ). When considering the alteration and seismic upgrade of existing marine structures, navigating the codes is further complicated. Existing building codes define thresholds that trigger the upgrade of existing elements, but these are not directly applicable to marine structures, introducing a variety of code interpretations. The Port of San Francisco’s Waterfront Resilience Program (WRP) has proposed seismic retrofits to improve the reliability of the seawall and marine structures along the Embarcadero. One key strategy includes wharf strengthening while adding a seismic joint between the wharf and pier. However, this joint introduces a structural modification to the existing pier and building, raising the question of whether a code upgrade is triggered for the pier structure. This paper discusses the impact of the seismic joint on the existing pier and code considerations for voluntary seismic upgrades of marine structures supporting buildings.