Demolition Derby
My buddy Dave Muck forwarded this story:
Workers are drilling holes into the two bridges at Interstate 225 and Interstate 25 so that on Saturday they can be imploded. The explosions are considered the fastest and cheapest option since the bridges are too tall to tear down.
We’ll end up drilling about 320 holes in two structures. Each will have an explosive charge put into it,” said Scott Gustafson with Demtech. “The whole blasting sequence only takes a 6/10th of a second. The rest of it is up to gravity. Gravity will bring it down.”
The bridges that are impacted are the old flyover bridge from southbound I-25 to northbound I-225, and the old lanes of northbound I-25 underneath (pictured, above).
T-REX crews will stop traffic on I-25 near 225 at 7 a.m. Saturday. They hope to reopen it within about 15 minutes but drivers are to expect at least a 30-minute delay.
Sounds like a fun show. If you’re in Denver, you might want to watch.
I had to do quite a bit of blasting to prepare for the foundation for the house I’m building. Fortunately, my house is not near any other buildings so they didn’t have to use mats. All I can say, blasting is damn impressive, but even more so when they’re specifcally not trying to contain it…
Man, they should bring those roads here. We could use them!
I’m thinking that if it’s only going to impact traffic for 15-30 minutes, they must not be bringing everything down, right?
How’re they gonna clean up that much concrete and rebar in 15-30 minutes??? I think that the T-REX reps are really a little too optimistic…
I can’t wait untill T-rex is finished. This project is nothing like the Big Dig in Boston (hate driving there). Sometimes I feel the freeways in the Denver Metro area are the same as Los Angeles (where I was born and raised) or worse.
I love implosions. Wonder where I could watch this one?
It’ll be on television…we can all watch
I’m not sure how far this got propagated in the news, but the word from T-REX for today is “Oops!”
The blast didn’t do the job, and they’re now trying to get it down by more conventional reasons.
wtched it on KUSA channel 9 and when the top bridge didn’t fall i heard someone in the background say “OH SHIT”. Poor CDOT they have a bad enough reputation as it.
Ch 9 news reported that part of the problem was that there was ‘more steel within the structure than expected’.
How could they not know how much steel was in the existing structure? Didn’t someone write that down somewhere?
Chad, what’s in the specs isn’t always what’s actually in the structure. (Though, it is nice for once to see that it was over-boult instead of under…)
I lived in West Orange, NJ, where Edison had a major lab complex. The lab buildings were among the first to use reinforced concrete – able to hold large tool & die equipment – we’re talking heavy stuff! In the ’70s they blasted the buildings, one blast every Saturday for several weeks – that’s when they found out how much over-kill Edison built into the concrete. The two bridges at the DTC in Colorado were about 31 years old, and there was a fair amount of “quesstimates” about the reinforcing. After the initial blast (and the “Oh, shit”), it took less than 30 minutes to break loose the ends of the remaining bridge and drop it and to restore the traffic flow. If they’d used the usual demolition techniques from the start, it would have taken about a week to get both bridges down and get traffic moving again along the new bridges, which were already in place and being used.