The bridges are each expected to be prefabricated, aluminum structures with abutments embedded at least 2 ft below existing ground surface elevation. Due to the lightly-loaded structures and ground sensitivity to heavy equipment, the bridge abutments will be reinforced concrete shallow spread footings, subject to the limitations discussed herein. Plan footing dimensions are indicated to be approximately 6 ft. by 12 ft. Total loads on the abutment footings are expected to be on the order of 400-500 pounds per square foot (psf).
The boardwalk is about 530 ft long with deck grade about 3 feet above ground surface (about one foot above high tide). Since this crosses the environmentally-sensitive marshland, design and construction is intended to minimize ground disturbance.
To prepare the report, CAInc reviewed available geologic, soils, and seismic maps; drilled and sampled test borings; hand augured test borings; and performed geotechnical engineering calculations and analysis to develop recommendations. CAInc analyzed subsurface conditions, completed lab testing, determined corrosion potential, and provided seismic design parameters. Recommendations were provided for spread footings and helical piles.