Hegenberger Overpass

Project: 23rd Avenue Overhead, Hegenberger Overpass
Owner: City of Oakland, California
Architects: John Carl Warnecke & Associates; Kaiser Engineers
Landscape Architect: Lawrence Halprin & Associates
Structural Consultants: T.Y. Lin & Associates
General Contractor: Oscar Holmes
Date Completed: 1963
Photographer: Morley Baer

Award of Merit - Pressed Concrete Institute, 1963
Citation - 10th Annual Progressive Architecture, 1963
Distinguished Achievement Award - Oakland Chamber of Commerce, 1964

The 23rd Avenue Overhead was designed to achieve a harmonious blend of function and aesthetics. The overpass is a major access route to the Coliseum and Oakland International Airport.

A 660-foot curving cast-in-place concrete girder bridge was praised by the 10th Annual Design Awards Jury of "Progressive Architecture Magazine" as a "Commendable design effort...in an area of construction activity seldomly explored architecturally."

Constructed of the lightest colored Portland cement available, its four 165-foot spans curve vertically and horizontally and are supported on tapered piers, which flair into the soffit of the girders.

This multi-million-dollar overcrossing was part of Oakland's Hegenberger Expressway Project. It bridges several railroad tracks and the proposed Bay Area Rapid Transit Tracks as well as a street. The first stage of construction provided for two 115-foot and one 70-foot-long gracefully sweeping spans combined with handsomely landscaped approaches.

The second stage had five spans consisting of a central 300-foot span together with 200-foot and 135-foot spans at each end. Concrete construction was chosen over steel because of its possibility for sculptural form and its greater economy. The prestressed concrete structure includes the use of precast "pan" elements to form the deck, and unique "V" shaped piers are used to support the 200- and 200-foot-long spans. This concept achieves construction economies and also results in an overpass of outstanding grace and beauty.