Optimization of Seawall Design at Alameda Marina

Seawall design and construction have advanced immensely over the past 1,500 years. Modern designs employ a wide array of construction means and are built with various materials. From a practical and economic perspective, selecting the optimal seawall for a specific site is an essential and challenging engineering subject. At Alameda Marina, highly variable site conditions required systematic evaluation of many types of seawalls to achieve a cost-effective design and minimize the risks for construction claims. The evaluation criteria for selecting seawalls included cost, seismic robustness, durability, constructability, considering possible underground obstructions, and environmental restrictions. As a result, three different types of seawalls were selected for construction: (1) a soldier pile and lagging system was selected for the seawall at the west segment of the shoreline, (2) a reinforced concrete L-wall on piles was selected at the central segment of the shoreline, and (3) a sheet pile wall with tiebacks and deadman was selected at the east segment of the shoreline. Compared to the preliminary concept design, the final design of the seawalls achieved a significant cost saving with improved constructability and minimal risks for project cost escalation.