The new section is 3 mi. (4.8 m) long (it has rubberized asphalt) and has six new concrete bridges (two highway bridges spanning the 100 ft. deep canyon and four wildlife crossings.
Ames Construction crews are completing the last stage of the $29 million Doubtful Canyon Widening Project, an Arizona Department of Transportation (ADOT) project located at an altitude of 6,000 ft. (1,829 m) in the Tonto National Forest in Gila County, Ariz.
“There is some paving to be finished and the completion of the last bridge,” said Curtis Bilow, a former project manager and Ames spokesman. “The project took an existing two-lane highway and turned it into a four-lane divided.”
The new section is 3 mi. (4.8 m) long (it has rubberized asphalt) and has six new concrete bridges (two highway bridges spanning the 100 ft. deep canyon and four wildlife crossings — single-span bridges for elk, deer and other animals to use). The project also is improving existing drainage systems, providing additional fencing to protect elk and other wildlife, and bringing in new signage, striping and guardrails.
SR 260 serves as the principal route for Phoenix residents seeking to escape the heat to visit the nearby mountains. The project began in October/November 2010 and should be complete this June.
The first major bridge is a five-span 650 ft. (198 m) long bridge and the one under construction is a four-span 400-ft. (122 m) long bridge.
“The wildlife crossings are working very well and have greatly reduced the amount of accidents,” said Bilow, whose firm’s headquarters are in Minnesota. “The new fencing helps to funnel the animals towards the crossings.”
The old section had no bridges and rebuilding the road required serious blasting (conducted by Ames crews) to create a new road base — more than 1.5 million cu. yds. (1.15 million cu m) of mixed geological rock was loosened and removed from the site. The pavement from the old road, 16,000 tons (14,515 t), was milled up and blended with new materials for the base course.
Because Doubtful Canyon is part of a national forest, managing environmental concerns are an important part of the project. Ames had to clear 82 acres (33 ha) of woods, primarily pines and was required to save as many trees as possible for replanting after the work is complete.
“We salvaged a significant amount of trees and set up a nursery,” said Bilow, pointing out that Arbor Car Specialist was brought in for this work. “Once the new road bed was completed, laying down new lanes began, but it is the bridge construction that is posing the major challenges — especially getting equipment down to the canyon’s bottom.
“On top of that,” continued Bilow, “we are within a quarter-mile of an impaired waterway and there are environmental restrictions. We had to implement erosion control measures and we had a full-time erosion control manager to make sure that we weren’t putting anything into that area. We also had to do monitoring and testing every time we had a one-quarter inch of rain or snow.”
Temporary roads were established using an excavator and bulldozer to bring the equipment down in order to drill the four bridge piers.
“Even the cranes had to be brought down in sections and then assembled,” said Bilow. “When we finished our work, we graded the roads, planted trees and made the area look as natural as possible. The bridges were the critical path. For the second bridge, the substructure is done and they just have to do the caps and the bridge deck.”
Ames is working with many stakeholders, including representatives from the national forest — who attended weekly meetings and participated in the planning — tree clearing and replanting, placing rock and other materials, etc.), a nearby Boy Scout ranch, state game and fish officials (because of the wildlife crossings) and federal authorities. Because the project exceeded $20 million, these officials reviewed all change orders and had to give their approvals.
Managing traffic also was a major issue, which affected work schedules.
“We couldn’t impact traffic from noon on Friday until 9 a.m. Monday and even during the day, it is pretty heavily traveled,” said Bilow, “so a lot of material ended up being moved at night. ADOT understood the many challenges we were facing and as long as you had all your safety procedures and traffic control devices in place, we were fine.”
As a company, Ames primarily uses Caterpillar equipment which it purchases from company dealerships in the many states where it operates. On this project it was using six 631 scrapers, one D10 bulldozer, three 773 haul trucks, several 375 excavators, and a 988 loader. The Groves 350 ton crane used for the project was rented from Southwest Crane.
“We have a great agreement and relationship with Caterpillar and have been using their equipment for the past 50 years,” said Bilow.
In the Phoenix area, Ames purchases its equipment from the local Empire CAT dealership.
Stuart Jansa has been the project manager for the Doubtful Canyon project for the past year and has about 30 workers on site. Scott Nielson is the Ames equipment manager for the region and the onsite mechanic is Mark Brooks, who has two or three mechanics at the work site to handle maintenance issues.
“The majority of the repairs and regular maintenance are done on site,” said Bilow, who added that Ames is bringing in electronic monitoring systems to help with vehicle maintenance.
“It’s giving us a better utilization of our equipment and it is generating cost savings and is extending the lifespan of various components,” said Nielson, who added vehicles used for the Doubtful Canyon project are being electronically monitored. “The mountainous terrain can impact the monitoring systems, but they work most of the time. When we get into tight areas, communications can be lost for a few minutes.”
While being in the mountains avoids the desert heat and dust, it raises other issues for equipment maintenance.
“The snow melted in mid-March, but it was a factor to be reckoned with and in the summer you get temperatures up to 95 fahrenheit,” said Bilow, “The weather is comparable to the mid-west. The rock was hard on the equipment and that was a whole extra level of maintenance and awareness. We worked through the winters and we also had a lot of rain up there, which has an impact on the crews and equipment.”
When Brooks needs additional mechanics, Caterpillar sends help to the site. Crews are on the job day and night and Brooks is able to have at least one mechanic with every shift. Ames has an equipment depot set up for maintenance work, storage of parts, tools, fuel and various oils.
“The nearest Caterpillar dealership is two hours away in Phoenix, which means that we have to have a bunch of spare parts on hand at all times,” said Jansa. “Before every shift the operators do an equipment inspection checklist and those are turned over immediately to Brooks, who determines which repairs are a priority. The system is working well and we’re rapidly learning which parts wear out faster and that helped us determine our purchases and repair schedules. The winter snow and monsoons and daily summer rains often shut down overall operations and delayed repairs.”
He added that the repair crews are very efficient and typically equipment is back on the job on the same day.
The explosives used for the blasting were safely and securely stored in a national forest structure.
Nearly 15 subcontractors were brought on board for the project, including American Fence for the Elk Fence; Arizona Highway Safety for the guard rails, permanent signs, and two tube bridge railings; Asphalt Busters for asphalt reclamation; Case Foundation for the drilled shafts; Combs Construction for asphalt work; Paradise Rebar for rebar supply and placement; Revegetation Services for SWPPP and soil stabilization; Road Safe for barricades and striping; Tpac for girders; and Arbor Care Specialist for the nursery and landscaping
Pre-planning was an important aspect, especially with so many stakeholders and subcontractors.
“The best thing you can do is to listen to everybody’s ideas,” said Bilow. “SWPPP meetings were held weekly to discuss the environmental concerns, which went a long ways. Potential problems were anticipated and we had solutions on hand when they arose. Safety was number one and we had a great safety record on the project.”