New York Construction
Strong Foundation Supports Eighth Avenue Tower - Tom Stabile

January 01, /2004

Marc rises 432ft into the city skyline, with a soaring crown accented by a flying column design.
But some of the most impressive work in the 435,000ft structure at 900 Eighth Ave. took place out of sight and in the structural underbelly of a classically compact Manhattan property.
Beneath this 45 - story giant is a muscle grid of cassion support, concrete walls and clusters of steel bars that help the structure straddle two subway tunnels that cross through the site.

The project schedule was tight. Excavation started in October 2002, the reinforced concrete superstructure was topped out in September and the building is slated for full occupancy this summer.

The project takes advantage of the promise in the Eight Avenue corridor, said Joseph Moinian, Chairman of the Moinian Group, the New York, N.Y. - based developer.

"When the site became available in 1999 we took the opportunity," he added. "In addition, full - block sites are very rare in New York City, especially an income producing site."

The $ 76 million building, designed by Frank Williams and Associates of New York, N.Y., will have 393 apartments on 37 floors; ground - floor retail; a four - storey, 550 - car garage; and a common floor with a health club, laundry room, child care center and other amenities.

Jack Kestenbaum, project manager for HRH constructions of New York, N.Y., said it took value engineering and scheduling to keep MARC on track.

"We came up with alternatives to make sure we could get to each stage on schedule," he added.

First came careful focus on the foundation and using solutions designed by structural engineer Rosenwasser Grossman Consulting and executed by foundation contractor Civetta Cousins Joint Venture and concrete contractor Century-Maxim Construction Corp.

Demolition of an existing municipal parking garage took place before HRH arrived on the job. When HRH took over, work to support the future building's load began with a caisson design.

The Civetta Cousins team began by driving thick structural steel tubes into the bedrock on either side of the tunnels for the B and D lines of the NYC Transit Authority, which turn under the site. Next, workers excavated around the piles and anchored clusters of reinforced steel bars to the rock throughout that area. Then the entire complex was encased in concrete.

Once Civetta Cousins completed that phase, Century -Maxim erected giant concrete walls to support the foundation.

"The way the engineer designed it to accommodate that was to create large structural beams, but they were huge supporting walls that were 20 ft or more high," said Tom Cardullo of Century Maxim. "They allow the foundation floor to bridge over the subway without putting any load on the tunnel."