Geotechnical Considerations for Development of a Fireboat Station at the Port of Long Beach

As part of the Port of Long Beach’s effort to expand and modernize several of its terminals and infrastructure, a state-of-the-art fireboat station will be reconstructed at Pier F Berth 202. The proposed fireboat station consists of a pile-supported fireboat bay on the waterside and a fire station building on the land side of an existing dike slope. Being an essential structure, the fireboat station is designed to be operational during the building code design earthquake (DE). The site for the fire station was developed several decades ago by constructing multi-lift rock dikes and placing dredged fill materials. During design earthquake, the fill materials are highly liquefiable and will potentially cause large lateral deformation and seismically induced vertical settlement. The buried rock dike, which may include potential armor rock and be susceptible to large lateral deformation during the seismic event, poses challenges to design and construction of the proposed fireboat station building. Among various options considered and evaluated through value engineering, jet grouting was chosen as the most practical and cost-effective option to improve the ground to mitigate lateral slope deformation and to support the fire station building. This paper summarizes the geotechnical investigation, site characterization, foundation options considered, and engineering analyses and criteria that led to developing the jet grout improvement scheme.