Deep Foundations at Beck Street Bridge
The Beck Street Bridge replacement project was part of a larger Utah Department of Transportation (UDOT) project, EXPRESSLink, that was designed to increase capacity to I-5 by adding express lanes in each direction from 500 North to the north interchange in Davis County. Bridges at U.S. 89, 1000 North, and 800 North were also replaced. UDOT used a design-build method to cut the overall construction time by nearly 50% and save significant project costs.
For the Beck Street Bridge, Malcolm installed twenty-four (24), 9-foot-diameter shafts with depths up to 135 feet. Installation was accomplished using the oscillator/rotator method, placing the casing in advance of the excavation of the shaft tip, and then extracting the casing during concrete placement. This installation was unique in that the shafts were tip grouted upon completion. With this process, the designers were able to account for less settlement in their design and could shorten the lengths of the shafts which provided an automatic competitive advantage at bid time.
Several utilities in close proximity to the site were a concern during drilling, but Malcolm’s crews exercised extreme caution to ensure that the lines were not compromised and the low vibration of the oscillator method added another level of precaution thus eliminating damage to the utilities.