Pier 57, located on the Hudson River at 15th street, was uniquely constructed by “floating” three hollow concrete caissons down the river. The caissons support the two-story steel and concrete pier building. Built in 1952, the pier is one of the biggest of its time and is recognized by both the New York State Historic Register and the National Historic Register as an engineering marvel for its construction.

In 2017, there were plans to renovate the pier for commercial use. When the caissons were inspected, a plague of water infiltration issues was discovered. The scope of repair included injection of a hydrophilic acrylate resin to repair the structure and stop leaks. PULLMAN was chosen because of our past grout injection experience and ability to assume likely unknown conditions, creating an accurate budget.

Crews performed non-destructive testing to locate existing rebar and find ideal locations for injection ports. Due to limited caisson entrances and exits, PULLMAN prioritized areas with safe egress in place before working with the general contractor to build new floors and staircases at other caisson entrances. Crews also used a containment plan to collect dust and manage air flow during repairs.

A custom grout resin-to-catalyst ratio was developed so that the grout would cure more rapidly with the separation plane of the crack and minimize the chance of the grout traveling to the other side.  To design this formulation, PULLMAN partnered with BDA Associates.  Through a series of mock-ups, the ratio of catalyst to resin was determined for the different sizes and locations of cracks.

The leaks were resolved within the owner’s schedule and no additional leakage has occurred, even with changing tides.