CN Grade Separation

  Project Location (map)  (1.81MB)
  Description of Project (Updated: 02/11)
  Funding    (Updated: 02/11)
  Schedule (Updated: 02/11)

St. Clair County is located on the west side of the St. Clair River across from Sarnia , Ontario , Canada .  With the Blue Water Bridges spanning the River and the Canadian National (CN) Rail tunnel beneath the River, St. Clair County is uniquely positioned on a prime international trade route.  The North American Free Trade Agreement (NAFTA) established this corridor as a direct link between Canada and Mexico.  

The CN Railroad yard facility in Port Huron Township provides access to the tunnel, one of only three international rail border crossings between Minnesota and New York .  Trains traveling to the United States from Canada first travel through the tunnel and enter the County at the CN Railroad yard where some are randomly inspected by the United States Office of Homeland Security’s Customs and Border Protection (CBP).  Due to the border crossing’s economic importance and increased security concerns, the CBP’s inspections can cause significant train delay problems at the Michigan Road , Griswold Road and Range Road crossings.  This results in substantial delays for local residents and emergency services.  CN Railroad business and CBP random inspections can cause trains to stop and backup, often blocking more than one at-grade crossing at a time.  

Wadhams Road Bridge

  Project Location (map) (Updated: 02/23/10)
  Economic Importance  
  Funding    (Updated: 02/23/10)
  Schedule (Updated: 02/23/10)
  Informational Mtg: Kimball Twp Hall 9/08/10
  Informational Meeting Handout (04/08/10)

St. Clair County Rd Comm. Wadhams Road Bridge Project Facebook Page

The bridge on Wadhams Road over the Black River is two-lanes wide with a five-foot wide raised sidewalk on the east side.  The road south of the bridge is four lanes wide from just north of Lapeer Road to I-69.  The approach north of the bridge is three lanes wide to North River Road .  The bridge has 12 spans and its total length is 530 feet.  

The substructure of the current bridge was built in 1941.  The deck was replaced and widened in 1977.  

The current 24-hour traffic volume is 16,270 vehicles with 11% commercial (trucks).  

To accommodate present and future projected traffic, the replacement bridge will be four-lanes wide with a pedestrian walkway.  

The nearest bridge across the Black River is 7.4 miles to the east at I-94/I-69, just west of the Blue Water Bridge .  The nearest bridge to the west is 6.4 miles away on M-136.   

If the structure is closed several detours would be in effect.  Cars and light trucks could cross at M-136 to the west or I-94/69 to the east.  The detour to the west is 14.7 miles.  The detour to the east is 13.1 miles.  The alternate all-season route would be over I-94/69 via a detour 15.3 miles long.  

Wadhams Road Bridge Progress Update - October 6, 2011 Stage 1 vs Stage 2 With the second bridge getting closer to completion, much attention has to be placed on connecting the two bridges together to crate on driving surface for the entire bridge.

All beams that are built for a bridge have camber designed into them.  The camber is how much a beam bows up when set upright.  Every beam must have camber designed into them otherwise the bridge may not be strong enough to hold even its own weight.

Once a load is applied to the beams such as the concrete deck, the amount of camber in each beam will decrease in order to support the load of the deck.  This change in camber is commonly called the deflection to the beams.  The remaining camber will then help support the load that will be applied to the bridge by everyday traffic. Because of the size of the beams and the length of the two spans on this bridge, the amount of deflection in the beams is expected to reach up to 7 or 8 inches.  This means that at the start of the deck pour for stage two, the surface of the stage two deck will be up to 7 or 8 inches higher than the stage one deck surface. After the concrete deck is poured on stage two, the beams will deflect, and the surfaces of stage one and two will then be at the same level.  Since we have so much deflection in the beams, we must build two separate bridges and then connect the two to make one driving surface.  Creating a gap and a closure pour between the two bridges allows us to accomplish this.

A view of the closure pour area from under the bridge.

All beams are in place and ready to be bolted together.  Once all bolts are tightened, placement of the pan decking and steel reinforcement can begin.

Screed rails are placed on supports to hold up the bidwell which is used to smooth the concrete to a consistent grade.

A bidwell gets set up then a dry run is performed.  The dry run is done to simulate the placement of concrete ad checks are then taken to project the thickness the concrete will be when it is poured.  Then during the pour, wet checks will be taken to record the actual thickness of concrete placed.  The wet and dry checks are then compared to see if they match within tolerance.

Much reinforcement steel and form work goes into a deck of this size.

All deck pours are completed at night unless the temperatures during the day are colder than specifications.  The closure pour area can be seen in this picture on the right.  The closure pour will be done once all the remaining deck pours are completed and the amount of deflection in the beams can be verified.

The sidewalk pour was able to be done during the day because the temperatures were quite cool.

Even before the deck is complete, the asphalt crews are onsite placing the approaches to the bridge.  An approach slab of concrete and a sleeper slab is poured at the ends of each bridge.  Once these are complete, crews are allowed to start work on the approaches.