Design and Construction of Driven Pre-Stressed Concrete Piles to Support Large Transmission Structures-Video

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Video Summary

The presentation covers the design and construction of foundations for five transmission structures at the Port of Long Beach: four tubular steel poles and one lattice tower. The project replaced century-old structures and raised transmission lines to accommodate larger cargo ships.<br /><br />The site posed unusual challenges: it had been reclaimed from tidal mudflats, had subsided by as much as 25 feet due to oil extraction, and contained soft marine soils, deep potentially liquefiable layers, contamination, and undocumented utilities. After evaluating several foundation systems, the team selected eight 24-inch prestressed concrete piles per structure, connected to concrete caps.<br /><br />Close collaboration among the designer, contractor, and pile manufacturer shaped the pile design and construction plan. Test piles and PDA testing confirmed significant soil setup and helped establish installation, restrike, and testing criteria. With careful cushion management, production piles achieved the required capacities, including demanding seismic and uplift criteria. The project was completed successfully, demonstrating that prestressed piles can be adapted for challenging transmission-structure foundations with thorough planning.

Keywords

transmission structure foundations

prestressed concrete piles

Port of Long Beach

seismic uplift criteria

soft marine soils

pile design and construction