Photo: Mark Langford Photography

The bridge includes a 700-ft-long cast-in-place section and a 1,200-ft-long precast beam section.

Work included widening and reconstruction of the lower-level road, which serves as a passenger loading area. Underground utility improvements include data and communication line installation, earth excavation and embankment, retaining walls, concrete paving, curb and gutter installation, and placement of concrete flatwork.

The general contractor, Archer Western Contractors, and specialty subcontractor Cardinal Mechanical used a method similar to an old mining technique. “Wood-box tunneling” avoided utility and traffic conflicts during hydronic piping installation.

Underground hydronic piping was installed by hand-digging the tunnel while shoring the excavation with large oak timbers. The pipe is installed and the void filled with grout. Unlike an “open-cut” method, this has minimal impact to surface operations, can be done in limited areas and go deeper without disturbing existing utilities.

The tunnel went between a parking structure and an existing terminal without impacting traffic flow, which meant two 16-in. and two 20-in.-diameter pipes were installed 20 ft below the roadway.

Key Players

Submitted by: Archer Western Contractors Ltd.
Developer/owner: City of San Antonio - Aviation Department
General contractor: Archer Western Contractors Ltd., Arlington, Texas
Construction manager: Jacobs Engineering Group, San Antonio
Architect: Parsons, San Antonio
Civil engineer: CEC, San Antonio
Structural engineer: Jaster-Quintanilla, Austin
MEP engineer: Shah Smith & Associates Inc., Houston