SuperPile 2017 Online Proceedings, (DFI)
Marine Wharf Piles of the “Greatest Generation’s” Military Machine Still Serving on the Pacific Coast
Brian O'Neill, P.E., G.E.
Marine wharves constructed hurriedly during WWII located at Oakland Army Base (Port of Oakland Outer Harbor) in San Francisco Bay served troop and supply ships to help win the war in the Pacific. Four large wharves (Berths 7-to-10) sat idle over recent decades, and experienced some damage during California's 1989 Loma Prieta Earthquake. The wharves are supported on over 9,000 concrete and timber piles, and virtually no information was available on as-built pile lengths, condition, integrity, and no knowledge of current load carrying capacity that could be relied upon. Along with Army base turnover for redevelopment, the wharves’ new tenant faced a dilemma of whether the structures have any residual service life, or require major reconstruction or demolition and replacement at high cost. The aspect of permitting hurdles and environmental impacts of working in the bay were overwhelming. After conventional static load testing for pile capacity was scrapped due to feasibility and costs, the engineering and construction teams collaborated to develop a detailed program to confront the challenge of pile capacity testing at the now active wharves. The team’s program included non-destructive dynamic pile testing procedures for evaluation of pile capacity, integrity, and length for both 1940s concrete and timber piles. The team’s pile program was completed successfully, with surprising results! Both in- and over-water and wharf backland operations were conducted safely with no incidents. This included construction crane and geotechnical exploration rigs plus heavy equipment on the wharves, with special marine environment safety procedures, mandatory training and workplans. Instrumentation / monitoring was utilized during pile testing and geotechnical exploration activities. The overall program, best practices, and lessons learned serve as a model for future testing needs on similar projects. Presentation to include photos and video along with technical information shown on slides.
|article #2696; publication #1031 (SP-2017)|