GUSTINE LAKE INTERCHANGE
PHILADELPHIA, PA
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As part of a $20.2 Million ARRA project managed by PennDOT, Duffield Associates assisted Hayward Baker with the design of micropile foundations for two new bridges.

The Gustine Lake Interchange moves nearly 100,000 motorists daily among City Avenue, Lincoln Drive, Kelly Drive, and Ridge Avenue north of Center City, near the scenic Schuylkill River and Fairmount Park.  Gustine Lake, manmade and fed by the Wissahickon Creek, was the historic watering hole for East Falls.  The lake was replaced by a large municipal pool, and the grounds now are the home of the Arthur Ashe Youth Tennis Center.

The interchange project includes the replacement of four structurally deficient bridges, the removal of a fifth bridge, and the realignment of ramps to create a new signalized intersection.  The improvements also include new lighting, signage, eight bio-retention basins, and substantial “greening” and landscaping (300 trees and shrubs).

Duffield Associates provided geotechnical and structural engineering for the 100 ton capacity composite micropiles, which consisted of grout-filled steel pipe.  The micropiles were designed to be socketed into rock and the reinforced concrete core included a high-strength, large-diameter steel tension bar.

Duffield Associates also provided engineering review of two static pile load tests, to verify that the rock/grout bond strength met the design requirements.  Duffield Associates provided verification load tests reports summarizing the data obtained from the load tests and confirming that the design requirements were met.