The $350-million renovation of the abandoned pier, designed by Emil H. Praeger to handle military transport vehicles and based on World War II pontoons (ENR 1/11/51 p. 46), includes mitigating corrosion to concrete elements, including prestressed, precast girders that sit atop three buoyant hollow boxes. Two 360-ft-long, 127-ft-wide, 33-ft-high caissons each weigh 27,000 tons. A smaller caisson, 367 ft x 80 ft, forms the top of the “T” to support the perpendicular head house at the front. At the bulkhead, the piles extend to bedrock, but “farther west off the coast, the rock drops off,” notes Peter Koklanos, senior structural engineer with McLaren Engineering Group. “The caissons are supported partially off buoyancy and partially off silt several feet below the water.”

McLaren designed repairs to the corroded concrete elements, dry chambers to accommodate new elevators and utilities, and elements to support future commercial live loads.

In order to preserve the historic integrity, crews are building a high-performance curtain wall that is “a high-rise lying on its side,” says Frank Fusaro, partner with Handel Architects. “That meant understanding how much the pier potentially would move and rotate around the existing joints. In the curtain wall, we integrated flexible joints to allow for that.”

McLaren also specified a two-layer system to protect against floods of 50- and 100-year return periods, says Koklanos. The primary system is a cast-in-place curb. To protect against another Superstorm Sandy, “we specified a temporary flood-barrier system, called Aquafence,” he says. “It looks like a folding chair made out of a series of steel parts and a plastic membrane. Braces keep it open. Water hits the vertical surface, and struts keep it rigid. We’ll preinstall anchors at the toe of the folding gate into the deck.”

The barrier elements will be stored within the building.