Abstract:
Accommodating heavy design loads, variable geotechnical conditions, and seismic impacts in foundation design is not particularly uncommon. However, when the foundations support some of the largest electric transmission structures in California and are situated on the banks of a major shipping channel in one of the most seismically active areas of the country, the task becomes increasingly more challenging.
The proposed presentation will detail the foundation design and construction process for a 300+ foot lattice tower and multiple tubular steel pole structures on the Cerritos Channel Relocation Project, located within the Port of Long Beach in California. The process was uniquely challenged in a number of ways; the most significant of which was designing for high lateral, overturning, and axial demands of 300+ foot tall structures while considering construction constraints such as overhead limitations and potentially contaminated soils within one of the country’s most active and historic ports.  Ultimately, the project team designed and constructed a driven, pre-stressed concrete pile and concrete cap system featuring some unique aspects of pile design to accommodate extreme foundation loading, variable geotechnical conditions, stringent project design requirements, and construction constraints.
The presentation will provide details on site history and area geology; the geotechnical investigation which revealed deep liquefiable soils; the design process, including a discussion of how non-standard aspects were incorporated into the design to facilitate construction; and the design and construction verification process that included a test pile program to determine pre-drilling installation methods best suited for achieving required embedment and geotechnical resistances. It will describe the various challenges encountered during design and construction, how these were successfully overcome, and how the lessons learned apply to the broader industry.