Third Time's The Charm

Story and Photos by Bruce Higgins | September 28, 2010

The small community of Helper, UT, lies in a narrow canyon between Provo and Price. Very heavy traffic passes through the town on US 6, connecting Interstate 70 from Denver to the east with Provo and Salt Lake City, UT. Traffic on US 6 departs Interstate 70 at Green River, UT.

Helper, located on the Price River, was named for the “Helper Locomotive” that was connected at the community rail yard to assist trains crossing Soldier Pass to the west. Without these added locomotives, most trains could not have climbed the steep inclines.

The US 6 traffic, much of which is big trucks, has been so heavy passing through Helper that local vehicles were forced to wait for long periods at the intersection with Main Street for breaks in traffic flow. The narrow road through the community slowed US 6 traffic significantly, and there were many accidents in recent years.

To address these traffic concerns, the Utah Department of Transportation awarded a $20.2-million contract to W.W. Clyde & Co., one of Utah's oldest construction firms, founded in 1926. The total length of the project is 0.848 miles.

UDOT let the project to bid three times. The first letting had all bids received in excess of 10 percent over the Engineer's Estimate. To reduce the cost, UDOT redesigned the project, changing from two bridges to one. That bid letting was again too much over the estimate. The third bid was on a redesign narrowing the single grade separation structure. Clyde was the successful bidder at that letting. Interestingly, more funding came available, and the original width was change-ordered for this project.

Besides the traffic and the narrow canyon, environmental issues of working in proximity to the Price River proved challenging. These challenges included maintaining access and safety to pedestrians along the roadways and an adjacent trail along the Price River. In addition, the environmental concerns included local avian breeding seasons, and the older buildings in downtown Helper could have been damaged by vibration from construction equipment. This required vibration monitoring and control during the critical phases of construction.

Typical of a small community, the visibility is high and could be subject to much criticism for the inconveniences of the construction work. The mayor of Helper even resides on the south end of the project and has an unobstructed view of the work and the traffic flow on US 6. In this intense situation, Clyde team worked hard to maintain a good relationship with the community.

Super Elevated

The project is a single grade separation structure on a curve, making the structure super elevated. US 6 highway is carried over Main Street. Right-of-way was limited and a serious concern for both design and construction. Within the right-of-way, on-ramps and off-ramps had to be built tight against the embankment. To accomplish this, Mechanically Stabilized Earth (MSE) walls were used to avoid sloped embankments. The MSE walls are also used to shorten the span of the structure.

When work was started, the first priority was to relocate existing utilities, including two welded steel water mains, sanitary sewer lines, overhead power lines, gas mains, and new fiber optics. These utility relocations were the biggest challenge due to the limited access in high congestion with continuous local and highway traffic flow. It took about one year to get all of the relocations accomplished.

After utilities were relocated, the priority was to build the on- and off-ramps on the southbound side of the roadway. These ramps would initially carry traffic through the construction zone while the structure was being built. Due to the close proximity of the Price River and the narrow canyon with the commercial and residential buildings using the land in the bottom of the canyon, there was no possibility of a detour out of the construction zone.

The concrete abutments or substructure were built on 14-inch H-piling driven approximately 35 feet to bedrock. Some of the piles required pre-drilling. The eight structural steel girders span 165 feet as a single span structure. These girders were supplied by Utah Pacific Bridge and Steel Co. Geneva Rock, a Clyde company, supplied concrete for the project. Asphalt paving was subcontracted to Nielson Construction Co.

As soon as the overpass was completed to partial width, traffic on US 6 was allowed in two lanes. This relieved the major traffic problems while work could continue out of the substantial traffic flow.

Three Awards

The project has been such a notable success for the community and UDOT, as well as the motoring traffic, that three major awards were given in 2007. The Associated General Contractors of Utah awarded the Clyde team the “Highway Project of the Year,” as well as the “Best Partnered Project of the Year.” In addition, Fred Jenkins, UDOT resident engineer for the project, was named UDOT Employee of the Year.

As part of the W.W. Clyde & Co. commitment to not only build better projects but also help build better community relations, the Clyde team built and donated a covered rest shelter on the adjacent hiking and biking trail. Throughout the project, the Clyde team worked well with the community. This shelter will be remembered as part of that good coordination with the community to complete a needed and difficult project.

Editor's note: Freelance writer Bruce Higgins retired after a construction industry career spanning over 40 years. He lives in Farmington, NM.