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Wednesday, January 11

I-10 at Amanda Street: this one slipped by us

Tonight - yes, tonight - crews will start setting up traffic control for a one-year project to replace bridge support abutments under the Amanda Street overpass on I-10.
Not sure how this one slipped by us, but it did. It's a small-potatoes project in terms of size, scope and duration ... yet still has a pretty big impact on daily drivers. First, what we're doing. Then the impact.

What is TxDOT doing?
We've found an issue that needs resolved pretty immediately. Recent bridge inspections showed the start of a failure in the abutments under the I-10 bridge over Amanda Street. An abutment is a lot like a shelf and is often attached to a large retaining wall and is anchored by bridge support columns sunk deep into the ground. On the Amanda Street overpass, these abutments are showing some wear and, before the wear becomes a problem, we're planning to replace these supports. We are not replacing the bridge deck, so this work will all happen without any bridge demolition.
In order to do that, though, we'll be shifting traffic around on the bridge deck itself to create some work space for our crews. The first phase will be crews working to shore up some of the shoulder area to handle highway traffic. With that done, we'll get to work on the abutment under the edges of the bridge deck, shifting traffic when we're ready to transition from one edge of the bridge to the other.

What will the impact be?
Right off the get-go we'll have the I-10 main lanes trimmed to just two lanes each way (there's three each way normally) over Amanda Street. We will be this way until early 2018. This starts tonight.
We'll also have Amanda Street closed under I-10 for the duration of this project. The detour will be Roland Avenue, J Street, Clark Avenue and Yucca Street. It's a bit round-about, but it'll get you where you need to go.
Though this won't happen for a few weeks, we will at one point also shut down two entrance ramps. The westbound ramp from MLK will close and the eastbound ramp from Roland will close simultaneously for a few months when we work on the outer edge of the bridge. This is because of the taper of the closure necking the main lanes from three lanes to two; we simply couldn't do the taper while safely maintaining these ramps. This will happen twice; the first time will be in February and will last a few weeks. The second will happen in March and will last about six months.
The bottom line: this will be a regular impact to morning and evening commutes on the east side of town, but it will be short-lived. This project is set to be finished by early 2018.

Other details for the intellectually curious
For the record:

  • Contractor is J3, a relative newcomer to TxDOT work
  • Construction costs are about $2.7 million
  • Project starts this week
  • Project wraps up early 2018 - about a one-year project duration
In doing this repair we're using a z-piling method to brace the bridge while we reconstruct the abutments. With corrugated sheet metal in place to provide stability, we'll be able to actually reconstruct the bridge's foundation without taking the bridge out of service. Here's an animation that shows the whole construction process:
When we're done we'll have a bridge ready for use for another full generation and more - one that will look quite a bit younger, too.