Seismic Retrofit of a 1960s Reinforced Concrete Marine Terminal with Perimeter Seismic Dolphins

A 1960s era California marine oil terminal was determined to be a possible collapse hazard in a major earthquake. Rather than replace the structures with an estimated construction cost of over $100M (plus millions more in operational downtime), a unique retrofit design was developed at a fraction of the cost to improve the seismic performance of the structure. Additionally, with creative scheduling and flexibility, the terminal was able to remain operational, at or near full capacity, for the duration of construction. The final retrofit design includes the installation of new seismic dolphins around the perimeter of the existing loading platform structure to limit global displacement demands on the existing supporting piles. The seismic performance of existing piles and deck beams are also improved with the use of fiber reinforced polymer (FRP) applications. The paper will discuss alternatives considered by the owner, the reasoning for the final selection, and discusses unique construction aspects and lessons learned during installation of this work. Construction for this project is occurring over two complete phases, with one phase nearly complete as of February 2016.