Demolition

A new look at memorable I-10 bridge demos

A new look at memorable I-10 bridge demos

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A new look at memorable I-10 bridge demos

A new look at memorable I-10 bridge demos

August 19, 2011

Last week we gave you an update on how the new Mescal/J-Six bridge is coming along...

You might also remember that the night the damaged bridge was taken down, the old Marsh Station bridge was also demolished just a few miles away. It was a huge project that required completely shutting down I-10 for the night.

Check out the video above for a quick look at the work involved with tearing down two bridges in less than 10 hours.

SR 260 improvements under way

SR 260 improvements under way

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SR 260 improvements under way

SR 260 improvements under way

July 27, 2011
State Route 260 – the road so often taken by Arizonans seeking a quick trip to cooler climates – is undergoing improvements, which will make its scenic drive a little smoother for motorists!

ADOT started construction earlier this year on the project that’s aimed at improving SR 260 between mileposts 269 and 272, just west of the Christopher Creek Campground. This portion is known as the Doubtful Canyon section and sits roughly 20 miles east of Payson.

The plan is to reconstruct the existing two-lane undivided roadway into a four-lane divided highway. As we showed yesterday, work is well under way.

Once construction is finished, additional improvements will include:

  • Six concrete bridges
  • Improved drainage
  • Additional fencing to protect elk and other wildlife
  • Rubberized asphalt pavement to minimize noise and create a smoother ride for motorists
  • New signage, striping and guardrails

The Doubtful Canyon project is scheduled for completion in fall 2012 and is part of a larger effort to widen the highway from Star Valley all the way to the Mogollon Rim. Three other sections of SR 260 have already been widened. The Little Green Valley segment is under construction now and should be finished this fall.  

Travelers may have noticed some traffic restrictions in this area. These are necessary to complete this project, but ADOT makes every effort to lessen the impact.

“There are times when there’s going to be traffic delays and as ADOT we understand that and we try to minimize delay times,” says ADOT Senior Resident Engineer Tom Goodman in the video above. “But safety is really our biggest concern on any construction project … so we just ask that motorists be considerate of the work we have out here and obey the reduced speed limits and be patient. It will be all done and then it will be a nice highway to drive on.”

For more information, check out the SR 260 Doubtful Canyon widening project Web page.

Blasts along SR 260 necessary in widening project

Blasts along SR 260 necessary in widening project

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Blasts along SR 260 necessary in widening project

Blasts along SR 260 necessary in widening project

July 26, 2011

Some terrain is so rough and rocky that even heavy-duty machinery can’t break through.

That was the case last Thursday when ADOT crews used more than 7,000 lbs. of explosives to remove roughly 8,000 cubic yards of material along SR 260, about 20 miles east of Payson.

And, they’re not done, yet…

ADOT is working to widen the three-mile stretch of two-lane undivided roadway into a four-lane, divided highway. By the time this project finishes next fall, roughly one million cubic yards of dirt and rocks will have been removed.

Crews are using bulldozers and excavators where they can, but blasting is the only way to get through some the rockier spots.

For the blast in the video above, 179 holes were drilled and then filled with the 7,354 lbs of Ammonium Nitrate Fuel Oil, a type of explosive commonly used on projects like this. The blasts are set off with a charge from a wire detonated from a safe distance.

More blasting will be necessary for this project.

Check back for another video with additional details on this project and the improvements planned and even more explosive footage of the blast.

ADOT to begin work on replacement bridge soon

ADOT to begin work on replacement bridge soon

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ADOT to begin work on replacement bridge soon

ADOT to begin work on replacement bridge soon

June 13, 2011

Talk about a quick turnaround … it’s been just three months since a fiery crash destroyed the Mescal Road/J-Six Ranch Road bridge in Cochise County and already ADOT has approved a contract to rebuild and reopen the bridge this fall.

Considering the process can normally take up to two years, it is clear this project is critical to the nearby communities.

You might remember that the bridge suffered heavy damage back on March 15 after two semi-trucks collided underneath it. The damage from the resulting fire was so severe that the bridge was demolished by ADOT a few weeks later on April 8.

But, with the bridge gone, so is the link between the communities of Mescal and J-Six Ranch, and that is why the replacement project is on a fast track.

In fact, construction is expected to begin early next month at the site located on I-10 at milepost 297, west of Benson.

The project includes replacement of four columns, retrofit of abutments, installation of new precast concrete girders, construction of the concrete roadway, placement of approach slabs, painting of the existing and new portion of the bridge, pavement marking and other related work.

Federal Highway Administration emergency relief funds, a shortened time frame for designing the replacement bridge and a quick construction bid process all have helped move the project ahead at a rapid pace.

Drivers in the area should know that detours have been in place since March 15, when fire damage to the concrete piers and steel girders required closure of the bridge, which was originally built in 1958. The adjacent pedestrian bridge was not damaged by the fire.

I-17 bridges in Munds Park ready for upgrades

I-17 bridges in Munds Park ready for upgrades

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I-17 bridges in Munds Park ready for upgrades

I-17 bridges in Munds Park ready for upgrades

May 25, 2011

The bridges over Pinewood Boulevard in Munds Park have been carrying Interstate-17 traffic for the past 53 years and now it’s time for some well-deserved reconstruction!

ADOT has already begun the project that will rebuild the bridges and ramps on I-17 at Munds Park, an area just south of Flagstaff . Work started last month and is scheduled to wrap up by fall 2012.

When the job is finished, motorists will have two new bridges each measuring 100-feet long (they’re now just 25 feet). The bridges will also be wider to accommodate an eventual third lane planned for I-17. A new sidewalk on Pinewood Boulevard is going in, too. It will allow pedestrians to cross safely underneath I-17 (see above video).

This update is necessary because there is more traffic now then when the bridges were built in 1958. Back then there was no development in Munds Park . The bridges are just inadequate for today’s traffic.

Drivers should expect some slowing of traffic due to this project – especially over busy holiday weekends. It is expected that delays at peak holiday travel times could reach up to 45 minutes … so please plan accordingly.

Project Timeline

April 2011 - Oct. 2011: The northbound bridge will be demolished, then reconstructed and I-17 will be repaved through the work zone. Because the northbound bridge is closed, motorists traveling northbound on I-17 will be directed to a detour that crosses over the median and utilizes southbound lanes. All on and off ramps will remain open.

April 2012 - Oct. 2012: The southbound bridge will be demolished, then reconstructed and I-17 will be repaved through the work zone. While this work is being done, the southbound bridge will be closed and motorists will be detoured over to the northbound lanes of I-17.

How to tear down two bridges in 10 hours or less

How to tear down two bridges in 10 hours or less

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How to tear down two bridges in 10 hours or less

How to tear down two bridges in 10 hours or less

April 15, 2011

In just 10 hours this past weekend, two bridges in southern Arizona were demolished in order to make way for something new.

All it took was some good planning, plenty of patience from motorists, a few enormous machines, and a ton of work by crews on the sites.

A little bit of background …

In November of 2009, ADOT began work on the I-10 Marsh Station Traffic Interchange in Southern Arizona -- a $10 million American Recovery and Reinvestment Act project that includes the extension of Marsh Station Road, drainage improvements, and the construction of a new traffic interchange to accommodate commercial truck traffic.

As it stood, the old Marsh Station Bridge had a clearance of 15 feet -- too low for most commercial trucks to clear. To avoid the bridge, trucks taller than 15 feet have had to maneuver a winding, two-lane, 67-mile detour.

(Note: Not until a nearby Union Pacific Railroad bridge is removed later this year, will most trucks be free to ditch the detour and safely pass through the new traffic interchange.)

But first things first, the old Marsh Station Bridge needed to come down. The only way to secure the work site and ensure the safety of both ADOT crews and the travelling public, however, was to close Interstate-10...forcing all local and interstate traffic into that same 67-mile detour!

After a lot of planning -- being careful to avoid Spring Breaks and other heavy-travel holidays -- ADOT set a date (April 8) and made arrangements to bring down the bridge, clean up the debris, and reopen the interstate, all in a 10-hour, overnight window.

The unexpected...

About three weeks before the demolition was set to occur, on March 15, two semi trucks collided under the overpass at the Mescal Road/J-Six Ranch Road Bridge about eight miles down the road from the from the old Marsh Station Bridge. The bridge was badly damaged from the resulting fire and would have to be replaced.

The task...

Since the interstate was already going to be closed, was it possible to safely get another bridge down in the same 10-hour window? Sure it was, and here’s what it took…

Breakdown by the numbers:

250:
The approximate number of tons of dirt that went down on the roadway below the bridges to act as a cushion for what the crews tore down.

1,480,000:
The approximate number of pounds of concrete removed during the demolition of both bridges. If you need a way to visualize just how much heft 740 tons is, it’s equal to the weight of about 120 adult male African elephants.

112,000 and 232,000:
The approximate pounds of rebar (112,000) and steel (232,000) that were removed during the take down of both bridges.

6:
The number of excavators used on both projects. Two excavators with scissor-like attachments worked on the Marsh Station Bridge demolition. Four excavators (two with the scissor-like attachments and two with hydraulic hammers) worked to bring down the Mescal Road Bridge.

45:
The number of seconds it takes us to show the Marsh Station demolition in this time-lapse video!