The Rt. 70 Bridge project involved the staged erection of two fixed bridges to replace a drawbridge constructed circa 1936 over the Manasquan River. The southern bridge was constructed first to hold both east and westbound traffic while the drawbridge was demolished, then, the northern bridge was constructed in its place.
Each bridge is approximately 720’ long and 47’ wide allowing for two travel lanes, shoulders and a sidewalk for both east and westbound traffic. The deck is constructed of reinforced high performance concrete. Six prestressed concrete girders spanning five precast concrete pier caps support each deck. The pier caps rest on precast concrete columns and are post-tensioned through the columns to the pile cap foundations. Precast concrete cofferdams having an architectural finish are used and serve as the forms for the cast –in-place footings. Foundation construction consists of 24” diameter steel pipe piles filled with concrete. In each foundation, there are between 26 and 37 piles that extend approximately 110’ to a dense sand layer.
In addition to the bridges there are four retaining walls, of both cast-in-place and mechanical stabilized earth type. Site work includes installation of more than 11,000’ of concrete pipe accompanied by approximately 145 inlets and manholes. Paving operations are responsible for the placement of over 25,000 tons of bituminous concrete. This project was completed on time and within budget.