T-REX Bridge Implosion
or: If something doesn't work right, improvise!

On Saturday, March 27, 2004, the T-REX project imploded two old bridges at the I-25/225 ("Full House") interchange. The bridges imploded were the old SB 25-NB 225 flyover and the NB 25 lanes underneath. New flyovers, bridges and tunnels had been built as part of the project, allowing for the two bridges to be demolished. Due to how they were constructed, the method used in other parts of the project could not be used to demolish these bridges. So, they would be dynamited at about 7:15am with Governor Bill Owens pushing the button.

I took pictures of the implosion from the back side of an apartment complex on the hill above the northeast side of the interchange.

The "Before" picture. The two bridges to be imploded are the brown ones. The gray top bridge is the new SB 25-NB 225 flyover.


The dust clears, and ... uh ... ummm ... wasn't the upper bridge supposed to fall, too?

Apparently there was a lot more rebar in the upper bridge than the demo crew thought. As a result, all the explosives did was blow out the concrete and bend rebar, but not enough to make the upper bridge collapse. In the picture above you can see rebar bent outward where the pier connects to the bridge deck. So, what now? You can't exactly just leave the thing sitting there in a weakened condition like that. The contractor, SECC, had an impromptu onsite meeting and it was decided to do what I would call improvise. They would chip away at the deck near each end of the bridge, weakening each abutment connection enough to (hopefully) cause the bridge to collapse. The large jack hammers which were used in other bridge demolitions on the project were brought in and started beating on each end of the bridge.

The large jack hammers chipping away at the deck near each end of the bridge.

After a while of chipping, the portion between the right abutment and pier collapsed.

When the deck near the left abutment had been weakened enough, the entire bridge collapsed.

The "After" picture. After the work of the large jackhammers, the upper bridge collapsed at 8:45am, an hour and a half after the explosives were supposed to have taken it down. Kudos to SECC for resolving what could have been a very bad situation.


Page created 3 April 2004
Last updated 3 April 2004