VCS performed a 75 year life extension feasibility study of the inverted pyramid structure located on the St. Petersburg Municipal Pier in St. Petersburg, Florida. The feasibility study included an on-site investigation into the condition of the concrete encased steel structure to assess options to extend the structure’s service life.
The pyramid, which was constructed in 1973, is located at the end of a pier which was constructed in 1926. The pyramid structure is comprised of a concrete encased steel frame and is supported by five caissons. Each caisson has 20 H-piles that are encased in concrete with 20 inches of cover. VCS was asked to identify the current condition of the structure and identify if the structure could be rehabilitated to extend its service life for 75 years.
VCS conducted a literature review of previous inspection reports; conducted a complete visual inspection of the interior and exterior in cooperation with the structural engineers from Kissinger and Campo; opened and repaired selected concrete excavations to visually inspect the structural steel; and conducted material testing. Concrete powder samples and carbonation measurements were collected throughout the structure to identify contamination levels of the concrete adjacent to the steel. Corrosion potential measurements were also collected in various areas of the structure to identify areas of corrosion activity in the structural members.
The feasibility study concluded that the structure was in good condition, with minor concrete and corrosion deterioration that could be mitigated, and that a 75 year life extension could be accomplished. The life extension strategy would incorporate various corrosion mitigation solutions suitable for the different structural components of the structure.