Helper Interchange project enhances traffic safety along U.S. 6

Contractor W.W. Clyde & Co. faced numerous challenges on this project, including high traffic volumes, environmental challenges working near the Price River and vibration monitoring and control for sensitive structures.

Motorists headed to various recreational areas in southeastern Utah this summer will see a big change – for the better – as they travel along U.S. 6 near Helper, Utah.

The Helper Interchange has been reconstructed as a grade-separated interchange, making for safer travel for local residents and the motoring public.

The Utah Department of Transportation awarded Springville, Utah-based W.W. Clyde & Co. the $20.2 million Helper Interchange project in May 2006. UDOT determined a need to improve the intersection because of an increasing number of vehicle crashes at the intersection in its original at-grade configuration.

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The Helper Interchange project called for the construction of a grade-separated interchange on U.S. 6 at Main Street with new on- and off-ramps. The improved interchange will allow motorists on Main Street to proceed on an at-grade road, while U.S. 6 motorists will drive over Main Street on an above-grade structure.

Safety was the main reason for the project, says engineer Fred Jenkins, who works with UDOT in Region Four, Price District. The utility infrastructure has also been updated in the area influenced by the footprint of the bridge, and an existing pedestrian trail was replaced.

“While W.W. Clyde & Co. was initially awarded a contract for phase one of the Helper Interchange, UDOT later issued a change order [which included phase two of the project] to widen the partially constructed two-lane bridge to its final configuration of four lanes,” says Randy Lingwall, senior project manager at W.W. Clyde & Co.

The change order meant that the project team had to construct the bridge in sections. The sequencing of the project underwent a major revision when UDOT issued the change order.

W.W. Clyde & Co. was awarded phase two of the project, which was moved forward and started several years ahead of what was planned, Lingwall says.

Jenkins says the utilities were the biggest challenge to overcome. There was a limited building area and numerous utilities had to be relocated, which took about one year.

“The utilities relocation required a lot of planning, coordination and scheduling so that the utilities could function [without interruption] while the work was being done,” Jenkins says.

In January, Jenkins received the Utah Associated General Contractor’s UDOT Employee of the Year award for his management of this project.

The project called for 8,400 lin. ft of welded steel pipeline (20- and 24-in.) for the waterlines; 3,500 ft of 12-in. PVC sewer line; and 1,200-ft of steel casing (18 to 36 in.) for water and sewer crossings under the roadway. A total of 11 crossings were constructed.

Scott Okelberry, vice president at W.W. Clyde & Co., says the new bridge spans 160 ft and involved constructing piling and abutments for four lanes of traffic. The bridge includes 900 cu yds of concrete; 925 ft of driven H-piles; 422,423 lbs of reinforcing steel; and 672,000 lbs of structural steel girders (weathering steel).

Given the location, high-traffic volume on U.S. 6 and environmental circumstances, W.W. Clyde & Co. faced additional challenges, including maintaining pedestrian access along roadways and trails, working along the Price River, working in compliance with restrictions for avian breeding seasons and vibration monitoring and control for local sensitive structures.

The project also called for surveying, traffic control, excavation, drainage, removals and demolition (including two buildings), constructing a cast-in-place concrete barrier and electrical work.

Retaining walls have been constructed along the mainline and ramp alignments. More than 53,000 sq ft of wall were built, including cast-in-place concrete coping on the top of all walls.

The project is 0.848 mi long and the roadway materials include 34,800 cu yd of borrow; 14,500 cu yds of granular borrow; 31,000 cu yds of embankment (for the bridge); 33,700 cu yds of retaining wall backfill; 8,500 cu yds of base course and 16,700 tons of hot-mix asphalt for paving.

Over the past two years, this project has received several awards including the UDOT Best Partnered Large Project (2007) and the AGC of Utah Highway Project of the Year (2007). Slated for completion this summer, the new Helper Interchange will provide both Helper residents and U.S. 6 motorists a safer route and gateway to southeastern Utah’s recreational areas.

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