Bridges

Bridging Arizona’s Freeways: How concrete bridge girders are made 

Bridging Arizona’s Freeways: How concrete bridge girders are made 

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Bridging Arizona’s Freeways: How concrete bridge girders are made 

Bridging Arizona’s Freeways: How concrete bridge girders are made 

Marcy McMacken/I-10 BWC Improvement Project / ADOT Communications
January 25, 2024
Crews using cement to fortify rebar and girders

Several concrete bridge girders have been placed throughout the I-10 Broadway Curve Improvement Project and by the project’s end, dozens of these girders will have been placed within the project area. 

Bridge girders are the beams that support the deck portion of a bridge which is the part of the bridge that motorists drive on. 

Many of the concrete girders for the I-10 Broadway Curve Improvement Project are made in the south Phoenix area, off 19th Avenue and Lower Buckeye Road.

When workers begin construction of concrete girders, they first place rebar within the girder formwork which helps to enhance the structural strength of the concrete bridge girders. Tons of rebar strands can be used for just one girder depending on the height and length of the girder that’s being constructed. 

Once the rebar is in place, the form cast that shapes the concrete girder is placed around the rebar. Concrete is then poured into the girder form cast. Workers then level and smooth the surface of the concrete and let it cure or dry for two to three days.  

When curing is complete, the form cast is removed from around the concrete and the new bridge girder is revealed. Workers then conduct inspections on each girder, making sure they meet the necessary design and safety standards needed. 

View the Behind the Scenes video on concrete bridge girders below.

Learn more about the I-10 Broadway Curve Improvement Project at I10broadwaycurve.com and download the free project mobile app called The Curve.

ADOT’s US 60 Pinto Creek Bridge replacement wins regional honor

ADOT’s US 60 Pinto Creek Bridge replacement wins regional honor

I-17 101 traffic interchange

ADOT’s US 60 Pinto Creek Bridge replacement wins regional honor

ADOT’s US 60 Pinto Creek Bridge replacement wins regional honor

June 12, 2023

Best Use of Technology, Medium Project, in America’s Transportation Awards

PHOENIX – An Arizona Department of Transportation project that replaced the US 60 Pinto Creek Bridge between the East Valley and Globe has received a regional honor. 

The 2023 America’s Transportation Awards named the effort Best Use of Technology and Innovation, Medium Project, for the Western region. The competition is sponsored by AASHTO, an association representing highway and transportation departments nationwide, as well as AAA and the U.S. Chamber of Commerce. 

“We’re grateful to see the Pinto Creek Bridge replacement honored among projects throughout the West, but we’re even prouder of what this improvement has accomplished for those who rely on this critical route for passenger and commercial traffic,” said Greg Byres, ADOT State Engineer and Deputy Director for Transportation. “ADOT engineers and the contractor used innovative design and construction approaches to create a safer and more reliable US 60 for decades to come.”

Completed in 2022, the $25.3 million project built the new bridge next to the one it replaced, with traffic continuing to use the old bridge until the new bridge opened. 

Among other innovative approaches used:

  • ADOT used a bid-alternative method for design, which allowed the contractor to determine economical and supportive foundation systems for each of the bridge’s three piers while taking into account the mountainous terrain.

  • To create retaining wall structures up to 30 feet high, ADOT engineers developed design standards and specifications for a micro-pile foundation system using high-strength, small-diameter steel rods.

  • A temporary access road was built to the floor of the steep canyon to provide access for heavy equipment, including a 400-ton crane that placed girders atop the piers, the tallest of which is 138 feet. 

  • ADOT partnered with Desert Botanical Garden in Phoenix to temporarily remove and then return hedgehog cactuses unique to the project site.

You can view photos of the completed bridge at flic.kr/s/aHBqjzWgRb. Carrying two lanes of traffic, the bridge is 695.5 feet long, has 10-foot-wide shoulders and can carry heavier loads than its predecessor, which was 72 years old.

The award was presented last week at the annual meeting of WASHTO, which represents departments of transportation in the West. 

Quick work safely restored I-10 traffic after crash damaged bridge

Quick work safely restored I-10 traffic after crash damaged bridge

I-17 101 traffic interchange

Quick work safely restored I-10 traffic after crash damaged bridge

Quick work safely restored I-10 traffic after crash damaged bridge

May 5, 2023

ADOT, contractor worked around the clock to shore up overpass near Willcox

WILLCOX – Arizona’s interstate freeways are essential corridors for personal and commercial travel. When an incident forces an extended closure, the Arizona Department of Transportation responds quickly to reopen the thoroughfare as soon as possible with safety the No. 1 goal. 

That’s what happened after a fatal semi-tractor trailer crash early Wednesday caused significant damage to the support structure of the US 191 bridge over westbound Interstate 10 just west of Willcox. Less than two days later, an ADOT project reopened the westbound lanes with a temporary support of steel members.

“I am proud of our ADOT team members and dedicated contractors who quickly identified and executed this emergency project,” ADOT Director Jennifer Toth said. “They safely set up detours, got the necessary team in place and worked around the clock to reopen this key corridor in less than two days.” 

Approved by ADOT’s Bridge Group, supervised by engineers in ADOT’s Southeast District and made possible by an emergency procurement, the project engaged Granite Construction Inc. as the prime contractor. Mere hours after the Arizona Department of Public Safety had completed its crash investigation, ADOT and the contractor began working nonstop to demolish the damaged bridge pier and erect the temporary support structure.

What the public can’t see when passing this temporary structure is the intensity of effort, the dedication and the commitment to safety that made it possible. 

A welder who was on site for nearly the entirety of the project told our engineers that he is 80 years old but still at it for his son’s company, which was a subcontractor. “I’ve retired six times but love what I do,” he said. 

Also generously assisting in this monumental effort were state, county and local law enforcement agencies that worked along the detour routes and southeastern Arizona counties and municipalities. The New Mexico Department of Transportation assisted with closing westbound I-10 in New Mexico. 

Now that a temporary structure is in place at the US 191 bridge at I-10 milepost 331, ADOT will determine a long-term plan. At a minimum, the pier, girders and deck where the crash occurred will likely need to be replaced.

There is never a good time for an extended closure, especially one that involves a lengthy detour from such a busy freeway. When it does happen, ADOT team members respond quickly and work as hard as possible with safety as their overriding goal. 

Temporary Structure

ADOT to replace SR 169 bridge deck over I-17 near Camp Verde

ADOT to replace SR 169 bridge deck over I-17 near Camp Verde

I-17 101 traffic interchange

ADOT to replace SR 169 bridge deck over I-17 near Camp Verde

ADOT to replace SR 169 bridge deck over I-17 near Camp Verde

April 19, 2023

Expect lane restrictions on SR 169 through this fall

CAMP VERDE  – The Arizona Department of Transportation will begin a project this spring in Yavapai County to replace the bridge deck on State Route 169 over Interstate 17.

The $6.2 million project is scheduled to start Monday, April 24, and extend through fall 2023. The work includes replacing the SR 169 bridge deck, which is the top surface of the structure motorists drive on. As part of the project, crews will also build a new concrete bridge deck, repair erosion at the bridge abutments and replace some sections of guardrail.

Motorists should expect SR 169 to be reduced to one lane only for east- and westbound travel during construction, with a temporary traffic signal regulating traffic. To reduce delays, work crews will limit other traffic restrictions to overnight hours. 

The work also requires overnight restrictions on Interstate 17 the nights of April 24 and April 25 while work crews demolish and remove the bridge deck. Southbound I-17 will be rerouted to the freeway ramps the evening of April 24. Northbound I-17 will be rerouted onto freeway ramps the evening of April 25.

For more information, please visit the project page.

Pardon our dust, we’re moving that bridge in Florence

Pardon our dust, we’re moving that bridge in Florence

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Pardon our dust, we’re moving that bridge in Florence

Pardon our dust, we’re moving that bridge in Florence

By Garin Groff / ADOT Communications
January 20, 2023
IMG_0294

This new bridge might seem unimpressive because it’s only one lane, but it’s got one unexpected trick up its sleeve.SR 79 bridge slide construction

It was built to travel -- at least a few feet -- and that’s what it’s going to do this weekend, Jan. 20-23.

Yes, ADOT is moving this new smallish concrete roadway section as part of an innovative way of replacing a bridge by sliding it into place, piece by piece. The process is continuing as we work on the second and final weekend of moving the structure’s components on State Route 79 in Florence.

Last weekend, Jan. 14-15, crews slid five of these segments into place to make up the northbound lane. And this weekend, we’ll move five sections of the southbound lane. Each segment spans 300 feet in length -- that’s as long as a football field. 

We’ve already discussed how the bridge slide process works, but we’d like to offer a final reminder about his weekend’s activity. And that the work will mean travel delays.

Traffic at the bridge over the Gila River will be narrowed to a single lane of alternating travel, regulated by a temporary signal. The restriction is planned from 8 p.m. Friday, Jan. 20, through 5 a.m., Monday, Jan. 23.

By Monday morning, Jan. 23, all sections of the new bridge should be in their permanent home and taking one lane of traffic in each direction.

Drivers should expect occasional but minor restrictions in the next few months as work crews wrap things up. Once all the dust has settled, the new, 1,500-foot-long bridge will feature one travel lane in each direction, 8-foot-wide shoulders and a protected pedestrian walkway.  You can find out more about the work on the SR 79 bridge replacement project page

Drivers in Cottonwood should prepare for closure of Pima Street for bridge project

Drivers in Cottonwood should prepare for closure of Pima Street for bridge project

I-17 101 traffic interchange

Drivers in Cottonwood should prepare for closure of Pima Street for bridge project

Drivers in Cottonwood should prepare for closure of Pima Street for bridge project

November 9, 2022

COTTONWOOD, AZ – Drivers in the Cottonwood area should prepare for a prolonged closure of Pima Street near Old Town Cottonwood while the Arizona Department of Transportation administers a local project to rehabilitate the Blowout Wash Bridge.

Pima Street will be closed to all traffic between Second and Third streets during construction. A detour will be in place east of the Old Town Cottonwood business district. The detour will allow residents living on Third, Fourth and Fifth streets to travel south to Main Street in order to access Pima Street west of the bridge closure.

The $828,822 project consists of replacing the existing bridge deck, replacing the bridge barrier, reconstructing the roadway approaches to the bridge and other related work. This will extend the life of the bridge, keeping it in good condition.

The project will begin in mid-November and is anticipated to be completed in early 2023.

The project is being administered by ADOT on behalf of the city of Cottonwood.

For more information, visit azdot.gov/cottonwood-blowout-wash-bridge.

Small town boasts a big piece of Arizona bridge history

Small town boasts a big piece of Arizona bridge history

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Small town boasts a big piece of Arizona bridge history

Small town boasts a big piece of Arizona bridge history

Kathy Cline / ADOT Communications
July 27, 2022

The town of Winkelman, on the border of Pinal and Gila counties, has a distinctive bridge claim to fame.

The Winkelman Bridge began life back in 1915, when the Pinal County Board of Supervisors appropriated $52,000 from a $500,000 bond issue to build it. Because Winkelman is located on the border of Pinal and Gila counties, Gila County agreed to pay half of the construction cost. At the advice of Assistant State Engineer T.M. Nichols, the structure would be built using multiple-span concrete arches.

In August 1915, R.V. Leeson, assistant engineer for the National Bridge Company, completed the drawings. As delineated by Leeson, the  structural type that would be use had been patented by Daniel Luten, with its distinctive horseshoe-arch profile.

In the fall of 1915, the construction bid was awarded to a Kansas company, Topeka Bridge & Iron Company, which finished the structure in November 1916. It's carried only local traffic since the construction of SR 177. In 1999 the Winkelman Bridge was restored with replicas of the original guardrails and is now a pedestrian-only structure.

The Superior-Mammoth Road was, for decades, an important route in Pinal County. The Winkelman Bridge is an important remnant of that route. In addition, the bridge is a great early example of the multiple-span Luten high arch and one of only 13 identified in Arizona that use these arches.

New A-1 Mountain Road bridge open to traffic ahead of schedule

New A-1 Mountain Road bridge open to traffic ahead of schedule

I-17 101 traffic interchange

New A-1 Mountain Road bridge open to traffic ahead of schedule

New A-1 Mountain Road bridge open to traffic ahead of schedule

June 7, 2022

FLAGSTAFF – The Arizona Department of Transportation has replaced the A-1 Mountain Road bridge in west Flagstaff ahead of schedule thanks to an innovative bridge construction method. The new bridge was opened to traffic Tuesday, June 7.

Crews used an accelerated bridge construction method known as a geosynthetic reinforced soil-integrated bridge system. Utilizing this method benefits drivers with a serious savings in construction time, allowing the project to be completed sooner than traditional methods. The A-1 Mountain Road bridge was demolished and replaced in a little over a month.

Crews will return later this month to put down final striping and roadway markings on the bridge. That process will require ramp restrictions.

ADOT first employed this innovative technique a few years ago when the agency replaced the Meteor City Road bridge over I-40 east of Flagstaff.

The $4.9 million project is located about 5 miles west of the I-17 junction along I-40.

For more information on the project, visit azdot.gov/i40-A1-Mountain.

A-1 Mountain Road bridge to be replaced in 40 days thanks to innovation

A-1 Mountain Road bridge to be replaced in 40 days thanks to innovation

I-17 101 traffic interchange

A-1 Mountain Road bridge to be replaced in 40 days thanks to innovation

A-1 Mountain Road bridge to be replaced in 40 days thanks to innovation

April 22, 2022

FLAGSTAFF – The Arizona Department of Transportation will demolish and replace the A-1 Mountain Road overpass along I-40 in Flagstaff in 40 days thanks to an innovative bridge construction method.

Crews will use an accelerated bridge construction method known as a geosynthetic reinforced soil-integrated bridge system. That means crews will create bridge abutments by putting in alternating layers of granular fill reinforced with synthetic material.

In order to replace the bridge, A-1 Mountain Road will be closed to all traffic over I-40 starting Monday, May 2.

During the 40-day closure, drivers will need to use the established detour route. Eastbound I-40 drivers wanting to exit A-1 Mountain Road will be detoured to Exit 191 to turn around and travel west to access A-1 Mountain Road. Drivers on A-1 Mountain Road who want to travel eastbound on I-40 will first travel westbound on I-40  and exit Hughes Avenue (Exit 185) to turn around and travel eastbound.

I-40 will also close overnight at the location of the bridge 16 times in each direction between 7 p.m. and 7 a.m. during the 40-day closure so crews can demolish the current bridge and construct the framework for the new bridge. Traffic will use the off- and on-ramps to detour around the closure.

Utilizing this method benefits drivers with a serious savings in construction time, allowing the project to be completed sooner than traditional methods. In addition, a new bridge deck will be constructed using a polyester polymer concrete that can be placed and cured in a matter of days rather than weeks.

The closure is expected to be lifted by Friday, June 10.

ADOT first employed this innovative technique a few years ago when the agency replaced the Meteor City Road bridge over I-40 east of Flagstaff.

The $4.9 million project, located about 5 miles west of the I-17 junction along I-40, is anticipated to be completed by this fall.

For more information on the project, visit azdot.gov/i40-A1-Mountain.

ADOT to replace Moenkopi Wash Bridge deck near Tuba City

ADOT to replace Moenkopi Wash Bridge deck near Tuba City

I-17 101 traffic interchange

ADOT to replace Moenkopi Wash Bridge deck near Tuba City

ADOT to replace Moenkopi Wash Bridge deck near Tuba City

April 15, 2022

TUBA CITY, AZ – Drivers near Tuba City need to prepare as the Arizona Department of Transportation begins a project to rehabilitate the Moenkopi Wash Bridge along State Route 264.

The bridge, located two miles east of the junction with US 160 in Tuba City, will receive a new bridge deck as well as new approaches creating a smooth transition on and off the bridge. Work will begin on Monday, April 18.

SR 264 will be reduced to one lane of alternating east- and westbound travel through the construction zone. Temporary traffic signals and concrete barriers will be used to control traffic through the work zone. Traffic will be shifted as the bridge deck is completed one half at a time.

Other work includes minor repairs to the bridge abutments, replacing guardrails and erosion prevention measures.

The $3.7 million project is expected to be completed by this fall.