Location: Dallas, TX

A. H. Beck installed 60,000+ cubic yards of drilled shaft concrete in shafts from 18” to 144“ in diameter for the Dallas Area Rapid Transit CMG3 Light Rail Extension project. The tight right-of-way and restricted working areas required single column/single shaft foundation design for much of the elevated project bridges. Live adjacent railroad lines ran the length of the project right-of-way, which presented challenges in placing large volumes of drilled shaft concrete in an uninterrupted fashion.

A. H. Beck utilized multiple drilled shaft installation techniques to install the large diameter foundations. Custom built 500 HP crane attached rotary tables to turn, set, and retrieve temporary and permanent casings up to 144” in diameter. High slump heavily retarded concrete mix designs were utilized on the larger diameter drilled shafts. Mineral bentonite slurry was used to stabilize shaft excavations where temporary casing alone could not effectively isolate the shaft excavation. Redundant concrete delivery systems were utilized in shaft sizes upwards of 120” in diameter.

GENERAL CONTRACTOR: Archer Western / Herzog, JV

OWNER: Dallas Area Rapid Transit Authority