NDOT Completes First Bridge Slide in Mesquite

A bridge in Mesquite was recently replaced using Dawn dish soap. 

A 1,000-ton, 45-ft-wide section of southbound Interstate-15 was swapped-out on January 10, using a bridge slide technique with liquid soap as lubricant. It marks Nevada’s first use of Accelerated Bridge Construction (ABC).

“While ABC techniques are new in Nevada, this approach has been used elsewhere with great success,” says Nevada transportation director Susan Martinovich. “It enables better workzone safety and construction efficiency.”

The bridge replacement is part of a $14.5 million upgrade to the I-15/Exit 120 diamond interchange. HDR Inc., Omaha, Neb., is the project manager. The undertaking, which began in May 2011, constructed a new 111.6-ft-long concrete-and-steel bridge over Falcon Ridge Parkway on temporary foundations alongside the existing structure. Next, the old bridge was demolished using hydraulic backhoes and hammer attachments. After the debris was cleared away, a new two-lane roadway deck took its place traveling at rate of 1.8-ft-per-minute with the help of hydraulic jacks and a pair of Teflon-coated steel beams. The modern structure is supported by five precast, pre-stressed bulb-tee girders. It took a total of 90 minutes, beginning at 9:45 p.m., to move the bridge 50 ft.

The entire process, however, including demolition and surface paving, took 56 hours; traffic was diverted using the on- and off-ramps. The slide replacement method reduces construction time by 6 months, while saving an estimated $12.7 million in delays and fuel costs, says the Nevada Dept. of Transportation, which held a technical seminar attracting 130 people from 23 states to learn about ABC.

The year-long project is improving West Mesquite I-15 exit and on ramps, rebuilding two bridges and creating a pair of one-way interchange roundabouts. In addition, Falcon Ridge Parkway underneath I-15 is being realigned and widened to four lanes, while being extended to the southwest to connect with Leavitt Lane. The project, which will employ up to 100 people, is scheduled to finish in May.