A new two-story, 70,000-square-foot maintenance facility on 17-acres is under construction by the Port of Long Beach (POLB), with plans for a vehicle storage canopy, materials storage building, and central plant.

Challenge:  The project site was reclaimed from the Pacific Ocean in early 1950, using hydraulic (dredged) potentially compressible fill. The remnants of a rock dike and dumped construction rubble were also found within the hydraulic fill. Prior to construction, geotechnical uncertainties emerged in this seismically active environment, including high potential for liquefaction and seismic-induced settlement.

Solution: Kleinfelder performed various studies to help POLB plan for site demolition, utility removal, and remediation of soil contamination, while locating buildings to mitigate interferences from buried rock dikes and rubble fills. To address the impacts of soil liquefaction, and considering the buried rock/rubble and proximity of existing structure and underground oil lines, a comprehensive study was performed to develop recommendations for ground improvements using Deep Dynamic Compaction (DDC). The study included geotechnical investigation, a full scale pilot test, and monitoring/testing during DDC implementation.

Project Results: Kleinfelder’s recommendations should help POLB realize savings of $2 million in foundation construction, costs by utilizing shallow foundations and ground improvement techniques for the maintenance building, instead of driven piles. Our recommendations should save another $500,000 by processing and reusing concrete and asphalt from site demolition as base material and general fill.