Construction: 1300 East Bridge over I-80

UDOT is rebuilding I-80 and I-215 on the east side of the valley. Included in the project is reconstruction of several bridges. This post is about the 1300 East bridge in Sugarhouse. This, along with the 1700 East bridge, were constructed in a unique way. The new bridge is built next to the existing bridge. When the bridge is completed, the old bridge is demolished and the new bridge is slid into place.

To the east of the existing bridge, abutments for the construction of the new bridge are constructed. The new bridge will be built "at grade", meaning it will be built at the final elevation. This means when the bridge is slid, it will move perfectly horizontally.
Notice the angled break or seam in the rebar. Left of this seam is permanent abutment. Right of the seam is temporary abutment only for construction of the bridge. Once the old bridge is demolished and the new is slid into place, this portion will be demolished.

The thickness of these abutments is shown here, as well as the seam between permanent and temporary abutments. The foundation for the temporary portion is less deep than the permanent one.

At the right end of the abutment wall is a small vertical bump out. Threaded rods will run through this portion which are used with hydraulic jacks to slide the new bridge.
The existing bridge is seen to the left.

The west part of the north abutment wall. Here we see another block through which rods will run when the bridge is slid. Also, we can see here how the new abutment runs under the entire old bridge.

A closeup of the west end of the north abutment wall. A near identical wall is being constructed on the south side as well.

A view showing the thickness of these walls. I estimate they are 3 feet thick.

The new north abutment wall is poured. You can see the permanent left portion has decorative texture cast into the surface. The temporary portion to the left needs no such decoration.
Two holes are seen running through the end block.

The massive steel beams are being installed. These beams sit on a large concrete beam below. There are large blockouts at the bottom of this beam, leaving only small portions of concrete resting against the abutment wall below. These blockouts are still full of wood formwork in this photo.

Closing the freeway for these lifts is done at night to reduce traffic impacts. I think it's worth some lost sleep to come watch.

A group of workers guide each beam end into place. Extreme care is taken to align each beam exactly where it needs to sit. They'll spend a half hour to get it just right.
Two beams, which have been connected with cross-bracing, are lifted at a time. I imagine they do this so they're more stable when placed.

A few days later, all the teams have been placed and more cross-bracing has been bolted on.
Here it's easier to see the blockouts at the bottom of the beam. This creates small blocks which the bridge will slide on.
We also see foam strips get placed along the edges of the steel beam top flange. The concrete deck panels will rest on these foam strips.

The ends of those large steel girders are now encased in concrete, along with the deck of the bridge.
New steel structure goes in north and south of the new bridge. At first, I have no idea what this structure is for.

My questions are answered later on when a new portion of bridge is built. This new portion extends onto those steel supports.
Again, here we see how the main bridge ends rest on small blocks of concrete. Under these blocks will lie low-friction surfaces for the bridge slide.

The eastern edge of the old bridge on the left, with the western edge of the new bridge to the right.

The far north and south ends of the new bridge rest on these pre-cast sections. The white strip shown is a low-friction surface for easy sliding. Once the old bridge is demolished, more of these sections will be added, giving the bridge a straight runway to be slid on.

Large steel guide beams will prevent the bridge from moving north or south on slide day.
On the left we see the large threaded rods running through the base of the new bridge. To my knowledge, hydraulic jacks will push or pull between the bridge and nuts on these rods. When the jacks are maxed out, they are retracted. The nuts are moved and the jacks push the bridge a little more.

Dawn dish soap is used to reduce friction for the slide.

Storm drain pipes are suspended beneath the bridge. After the slide, these will be tied into other drain pipes. The black hoses draped over the side are hydraulic lines for the jacks. They all lead to a control station and pump on the bridge.

The freeway and 1300 East are closed, and the old bridge is taken down. An army of excavators removes the old bridge in a matter of hours.

Slide day! I wish I had a better view. It moves so slow you really have to watch closely to see movement. I'd guess it moves about 3 inches per minute. The intersections on each side have to be reconfigured to fit the new bridge and new freeway ramps. This is the top of the Eastbound I-80 on ramp. The truck at the right is a mini concrete plant. Cement, aggregate, and water are carried on the truck and mixed on-site. This is fast-curing concrete. The ramp needs to be open in a matter of days, so rapid curing concrete is a necessity. Crews work 24 hours a day to get the new bridge and ramps ready for traffic.
Here is a great video of the demolition and slide.

More work on the south intersection. After this asphalt goes down and some striping, the bridge will be open for traffic.

New concrete barriers being poured. The near barrier is done with a slip form machine. A machine takes in concrete and extrudes the shape off the barrier as it crawls along. The far barrier is shaped by formwork. They can't use a slip form machine here due to the short length and the tight radius at the left.

New bridge is open for traffic! 1300 East only had to be shut down for a few days. If they'd used a more traditional method of bridge building, they would have demolished the old bridge and built the new one in place. 1300 East would have been closed for months in that case.