Whitestone Bridge
Bronx Terminal
Flushing Town Center
38 Delancy St.
Williamsburg
Norfolk St.
Corning, N.Y.

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Whitestone Bridge


Project:
Whitestone Bridge – Replacement of Bronx Approach

Owner: 
MTA – TBTA (Tri-Borough Bridge & Tunnel Authority)

Overall Contract Value:
$192,000,000.00


News Article

Client:
Conti Corp

IFS Contract Value:
$12,935,000.00

PROJECT OVERVIEW:
The Bronx-Whitestone Bridge was built ion April 29, 1939 and carries I-678 across the East River, connecting The Bronx with Whitestone, Queens in NYC. This toll bridge carries 200,000 vehicles each day and has a main suspension span of 2300 feet. This contract is to replace the Bronx approach.
The original contract includes design, furnishing, and installing 772 mini-piles with capacities as high as 150 tons. Additionally, the contract called for 15 pre-production static load tests to 250% of the design load. Approximately one-third of the piles were installed from underneath the existing bridge.

Whitestone Bridge

NOTEWORTHY:
The soil conditions at this project site presented many challenges to the bidders. Underlying the upper fill and organic soils, are layers of dense silt and sand and hard clay, infused with cobbles and boulders. The depth required for capacity lead to drilling into the underlying decomposed rock as well as bedrock. Typically, these soils would require multiple drilling methods including percussive drilling.
To make the project more challenging, an extremely small settlement criteria of ¼-inch was established for the existing bridge, believed to be supported largely on spread footings.
To resolve all of the challenges simultaneously, Intercoastal proposed the following:

    • Acknowledge that a pneumatic down-hole-hammer (DHH) would be required to drill effectively through the tough soils and to the depths required.
    • Drill with Reverse-Circulation (RC) to reduce the volume and pressure of air required to power the DHH and flush the drill cuttings.
    • Drill with RC drill rods with the same outside diameter as the DHH bit to assure that the drill hole remained stable throughout the drilling.
    • Grout through the RC rods and through the DHH bit as the rods are withdrawn to assure that high-quality grout is placed to the full depth.
    • Convert approximately 100 of the piles with the lowest headroom restrictions to “caissons” socketed into rock.

    Whitestone Bridge

    Whitestone Bridge





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