Second Avenue Bridge – I-94 Modernization Project

Second Avenue Bridge

The new Second Avenue bridge is an engineering marvel that has the distinction of being Michigan’s first network tied-arch bridge. “Network” refers to the numerous cables that are crossed from the top of the arch to the part of the structure supporting traffic. Once completed, the new bridge will connect the neighborhoods located on the north and south sides of Second Avenue, and provide enhanced mobility for pedestrians, bicyclists, and motor vehicles.

The bridge will feature one car lane in each direction, 9-foot-wide sidewalks, and 8-foot-wide bike lanes. A variety of environmentally friendly aesthetic treatments have been added, including approach landscaping and LED architectural lighting.

The skeleton of the new bridge is being built off-site at the Wayne State University Palmer parking lot. At the same time, construction crews worked on-site building the bridge foundation and abutment walls along the I-94 freeway.

The 1,100-ton bridge skeleton will be rolled across Lot 22 to Second Avenue into its final position over I-94 using self-propelled mobile transports (SPMTs). SPMTs are multi-axle rolling platforms that can move the heaviest loads. They can be operated mechanically or remotely.

The Second Avenue bridge is expected to reopen to traffic this fall.

Fact Sheet

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Detour Map

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Press Release

I-94 Closing for 5 Days

FAQs

Bridge Facts

What is so unique about the new Second Avenue bridge?

The new Second Avenue bridge will be the first network tied arch bridge in the state of Michigan. “Network” refers to the numerous cables that will be crossed from the top of the arch to the part of the structure supporting traffic. Once off-site construction is completed, it will be moved across the expressway and bolted into place over I-94. The Second Ave bridge is the first skewed and unbraced network arch bridge to be constructed in the US.

Network. Refers to the orientation of the cables, they will be crossed from the top of the arch to the part of the structure supporting traffic.
Tied-arch. The ends of the arches are “tied” so they cannot spread laterally as the weight of the concrete deck, vehicles, and pedestrians are applied.
Skewed. The bridge deck is not a rectangle. It has two acute corners and two obtuse corners. This geometry is required to accommodate frontage roads and adjacent properties at the site.
Unbraced. There are no lateral bracing members between the arches.

Where is the bridge being constructed?

What are the dimensions of the new bridge?

How will the new the bridge connect neighborhoods on either side of I-94?

What is the difference between the Taylor Gateway tied-arch bridge and the Second Avenue network tied-arch bridge?

The visible difference between the two bridges is in the arrangement of the hangers, the part that ties the bridge deck to the arch. Tied-arch bridge hangers are arranged vertically while those of network tied-arch bridges are arranged diagonally and intersect with at least two other hangers. The network tied-arch bridge is a stiffer structure and provides an improvement to the tied-arch technology. Its loads are distributed across a wider network of hangers, which reduces the stress on individual hangers.

There is also an economic advantage to the network tied-arch bridge. Its multiple paths allow for a design of slender arch sections that translate to cost savings over a conventional tied-arch bridge.

How long will the bridge last?

What is the cost of the new Second Avenue bridge?

Design, Build, Move

Who are the primary contractors on this project?

Why did MDOT choose this design?

How will the bridge be moved and how long will it take?

The bridge will be moved during daylight hours in two stages:

Stage I:

This summer I-94 will be closed to traffic for approximately seven days.
The bridge skeleton will be lifted onto a Self-Propelled Mobile Transport (SPMT), rolled across Wayne State University’s Lot 22 at 5 mph to an area behind the south abutment, and turned. Then it will be launched over the top of the south abutment so that another set of SPMTs located down on I-94 can lift the leading end of the bridge span and roll it across I-94 onto the north and south abutments.
Ongoing, thorough inspections will be performed during and after the move by MDOT, the designer and the contractor to confirm that no damage is/was done during the bridge move.
Once the bridge is in place, construction crews will install reinforcing steel and pour the concrete bridge deck. The concrete will be wet-cured for a minimum of seven days, the standard for bridges in Michigan.

Stage II:

This fall I-94 will be closed to traffic for approximately five days.
A second stage of post-tensioning will be performed to secure the bridge cables.
Inspections continue by MDOT, the designer and the contractor to make sure that the bridge is 100% safe and secure.

What is a Self-Propelled Mobile Transporter?

Safety

How will the bridge move impact local businesses, major employers, residents, etc.?

What is MDOT doing to ensure that the bridge is built and installed to the highest safety standards?

Safety is our priority. Our engineers and consultants are fully aware of the structural challenges facing such a major undertaking as an off-site construction and move of a multi-ton bridge. We have constantly studied, revised and tested our bridge calculations to make sure that ALL questions and concerns are addressed and meet final approval of our independent design checkers, inspectors and on-site supervisors. NO post-tensioning or cable adjustments will be made over live traffic on I-94; therefore, the expressway will be closed. This was unanimously agreed upon by MDOT, the design team and the contractor in the interest of safety.