Investigation and Initial Stability Analysis of a Wharf on Severely Deteriorated Steel H-Piles
The wharf at the Fore River Shipyard was built for shipbuilding circa 1960; recently, it was home to the USS Salem, a permanently-moored retired US Navy heavy cruiser that served as a museum. True to its intended purpose, the wharf is a robust structure comprised of a thick reinforced concrete superstructure supported by many steel H-piles. In 2013, Simpson Gumpertz & Heger Inc. (SGH) and Appledore Marine Engineering, LLC (AME) performed a condition assessment of the wharf at the behest of the owner who wanted to identify understand its remaining service life and prudent repairs. The team designed an investigative plan to assess the major elements of the structure, but then had to change this approach upon discovering that many of the H-piles were significantly deteriorated, some with full thickness section loss at the low-tide elevation. The focus of the investigation pivoted to understanding the collapse potential of the wharf. Engineer divers collected measurements from the piles while the team estimated the remaining strengths of these piles using AISC methods. The team used the estimated pile strengths in conjunction with three-dimensional, non-linear analyses to assess the likelihood of collapse and possible collapse mechanisms. With a better understanding of the collapse potential, the team could advise the owner on the risks associated with keeping the facility open.