Major interchange revamp relieves congestion HDPE pipe provided an alternative solution to the original plan for this ADOT design- build stormwater project in Surprise, Ariz. The pipe met ADOT specifications, reduced costs, and shortened the construction schedule. Fabricated manholes were produced at the Phoenix manufacturing plant. The pipe, manholes, and other fittings were delivered to the jobsite on a just-in-time schedule.
Connecting the smaller laterals to the main 54-inch lines was done using ADS Inserta Tees. They provided quick and economical watertight connections for 18-, 24-, and 30-inch HDPE pipe.
completed within that eight-month window to complete the overpass so everything on Bell was very accelerated. A big part of our concept was diverting traffic onto westbound Grand Avenue-U.S. 60 — which would require the stormwater runoff going into a storm drain under- neath the westbound lanes of U.S. 60. We had to get that completed as quickly as possible.” The intersection closedApril 1, 2016, and reopened just before Thanks- giving — less than the seven months mandated. The new interchange is a median urban diamond design, which has connections at the center rather than ramps to the right of Grand Av- enue travel lanes. The design minimized the impact on neighboring shopping centers and businesses by not requiring ADOT to acquire as much property. A Burlington Northern and Santa Fe (BNSF) railroad track runs along Grand Avenue. The grade rail crossing at Bell Road becomes impass- able when trains travel across it, resulting in additional delays and the potential for train/vehicle collisions. “Because this was a design-build, we opted to realign Grand Avenue closer to the railroad tracks. By doing that we restricted all the storm- water drainage that was to go between the railroad tracks and Grand Avenue,” Brunker said. In the initial design, stormwater was to flow in a concrete-lined open ditch channel between the tracks and Grand Avenue. Another consid- ered alternative was to bury large-diameter reinforced concrete pipe. Instead of either one of those alternatives, it was decided to use two runs of 54-inch-diameter high-density polyethylene (HDPE) pipe. This would allow Brunker and his crew to combine the offsite flows adjacent to the BNSF railroad tracks with the onsite flows coming off Grand Avenue. Running the pipe underneath Grand Avenue made it possible to reduce the height of the bridge, shorten the ramps, and keep the established landscape areas.
Twin stormwater pipeline provides path to solve Arizona highway realignment.
To alleviate traffic congestion at one of the busiest intersections in Maricopa County, the Arizona Department of Transportation (ADOT) decided to build a new overpass; add roads, lanes, and ramps; plus make other critical improvements. Located 45 minutes northwest of downtown Phoenix, Surprise has a population of 130,000 and is the spring training home for the Texas Rangers and the Kansas City Roy- als. Contractor Coffman Specialties, Inc. (San Diego) was given eight months to complete the $41.9 million design-build project at the inter- section of Bell Road and Grand Avenue. It was part of the Maricopa Association of Governments’ (MAG) Regional Transportation Plan approved by county voters in 2004. Funding sources included a county half-cent sales tax for transportation projects and a contribution from MAG’s federal highway funds. According to the plan, a portion of Bell Road would have to be closed, with the construction schedule fitting between the holiday shopping season and the start of spring training. Both events bring higher-than- usual volumes of traffic. “The city and ADOT gave us a short time to close down Bell Road because they didn’t want work going on during spring training, plus they wanted everything on Bell Road open by Thanksgiving for the holiday shopping season,” said Jason Brunker, P.E., the Coffman engi- neer responsible for the project. “They wanted everything on Bell Road
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february 2018
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