Photo essay: Cutting the old Fillmore bridge down to size - Phase 1After 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).
Westside Pioneer article and photos