Photo essay: Cutting the old Fillmore bridge down to size

Two track excavators use hydraulic-ram attachments to break up the north side of the old Fillmore/I-25 bridge over I-25 at about 1 a.m. Sept. 11. The photo was shot looking south from an I-25 travel lane. The interstate was closed in both directions for the work. At left in background can be seen the headlights of northbound vehicles being diverted to the Fillmore off-ramp so as to get past the interchange. The layer of dirt under the bridge was placed there to protect the driving surface from chunks of concrete that were being knocked loose. The girders for the new, just-opened south bridge can be distinguished from the old bridge, as their undersides are straight while the older ones are curved. (See photo at the bottom of this page for what the bridge looked like in the morning.)

Photo essay: Cutting the old Fillmore bridge down to size - Phase 1

       After the new south bridge opened to traffic Sept. 9, the partial demolition of the old Fillmore/I-25 bridge's northly half got under way the afternoon of Sept. 10 and then continued through the night.
       Motorists Sept. 11 found that northside deck gone and nothing left but the structure itself amid a maze of rebar.
       That remainder of the old bridge's north side is to be knocked away in the coming week in the next phase of the operation. The schedule tentatively calls for that to occur overnight Monday and Tuesday, Sept. 14-15.
       The reason the north half of the old bridge is being taken off is to make room for the new north bridge, which needs to be built in that space, according to Ted Tjerandsen of Colorado Department of Transportation (CDOT) project consultant Wilson & Company.
       The roughly 25 feet on the south side of the old bridge is to remain in service for the time being, carrying two lanes of westbound traffic until the new north bridge is completed in a few months. Then the rest of the old bridge will be demolished, according to plans.
       Concrete barriers, bolted into place, separate the portion of the bridge still in service from the portion being torn out.
       Caissons for the new north bridge will start being installed as soon as the demolition is done, Tjerandsen said. This work is anticipated to start Sept. 16-17, he said, dependent on weather and administrative factors.
       During the Phase 2 demo work (occurring at night), the interstate and Fillmore Street will be closed at the interchange; during the caisson activity, only intermittent lane closures are expected.
       The south bridge opening/old-bridge partial demo is a milestone in the $15.1 million project to replace the 55-year-old Fillmore interchange. CDOT hired SEMA Construction as the general contractor. The demolition contractor is Backhoe Services of Commerce City.
       The deck removal Sept. 10 was preceded by a subcontractor using a diesel-powered machine and diamond-tipped blades to saw the old bridge deck lengthwise. According to Tjerandsen, the cut followed the line where the old bridge was widened to the north in the 1970s. So the structural stability of the bridge will not be compromised by removing that portion.
       This was followed that night by Backhoe Services bringing in two large machines called track excavators. Equipped with hydraulic ram attachments, they beat on the segment north of the saw cut, a section at a time. As they did so, concrete chunks fell to the interstate below, which had been covered with a layer of dirt to protect the driving surface.
       All the dirt debris was cleaned up by early morning (although a bit later than the 5 a.m. deadline, Tjerandsen said).

Two track excavators demolish the north side of the old Fillmore/I-25 bridge during overnight work Sept. 11. LEFT: The machine on the western portion. RIGHT: The machine on the eastern portion. The concrete barrier (just visible in the lower right part of the photo) separates the south side of the bridge - the part that's still being used for traffic - from the north side that's being removed. The straight line just left of the barrier shows where a diesel-powered saw cut through the deck beforehand (see photo farther down on page).

A view looking east shows both track excavators at work demolishing the north side of the old Fillmore/I-25 bridge the night of Sept. 10.

LEFT: During the afternoon of Sept. 10, Bobby Dempsey of Concrete Cutting Company makes the first lengthwise cut along the old Fillmore/I-25 bridge, preparatory to demolition work. Meanwhile traffic was passing by on the south side of the bridge (on the other side of the concrete barrier), Behind Dempsey is David Ramsdale, owner of Backhoe Services, the demolition contractor. RIGHT: Another view from just north of the bridge during work that night. Rebar is exposed amid chunks of concrete falling. The man in the blue bucket is cutting rebar with a torch, as needed.

This was how the Fillmore/I-25 bridge looked the morning of Sept. 11, after the deck had been removed from its north side the night before. The structure beneath that segment is to be removed in overnight work Sept. 14 or later. Note the new south bridge, just to the south of the old bridge, which started carrying traffic Sept. 9. The photo was taken looking southeast from the Kum & Go parking lot at Fillmore and Chestnut.

Westside Pioneer article and photos
(Posted 9/11/15; Transportation: Fillmore/I-25)

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