Tim MacDonald
Senior Member
July 30
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QEW - Mississauga/Credit River Project
- Thread starter adma
- Start date
just east of the creek
Active Member
Driving past the QEW bridge this morning there appears to be a spate of new activity. It looks like some preformed closed steel spans have been delivered and installed/positioned(?) on the approaches to the bridge piers on the east side, but well back from the river. There is also a section of open steel truss work being assembled between the current location of the spans and the river. So I am assuming the steel truss work would be used to roll? push? the steel spans into position over the river? Does that make sense? It was hard to get the full appreciation of the work being done as we crossed.
just east of the creek
Active Member
I may have answered my own question. Excerpted from a NSBA White Paper. Incremental launching. THE incremental launch represents another prefabrication technique recently adopted for steel bridges. This technique is particularly useful when traffic, site -More- Speeding bridge superstructure construction, page 5 conditions, or environmental issues restrict the size and amount of construction equipment permitted below the bridge. The technique also improves safety because crews work close to ground level. Here the contractor excavates a large launching pit on one or both abutments. Crews preassemble a section of the steel bridge superstructure in the pit atop a system of bearings, and then push or pull the section incrementally across the awaiting piers. Roller bearings positioned at the girder centerlines on the pier caps carry the weight of the bridge sections and facilitate their movement from pier to pier. Push and pull equipment includes hydraulic thrust pistons, motors, cables, and sheaves. The technique applies only to bridges with straight or constant curve profiles. Since the cantilevered bridge sections may deflect significantly, contractors will usually attach a trussed skid or launching nose to lead the first steel bridge section. The skid will slope upwards a distance somewhat greater than the anticipated deflection. In some cases the launching nose is unnecessary since the successive bridge piers form a continuous downgrade that’s greater than the deflection of the cantilevered section. Incremental launching has been successfully applied to the construction of a 1630-ft steel bridge for Highway 20 in Iowa, carrying traffic 137 feet above the Iowa River. Each of two parallel steel superstructures consist of four 11.3-ft deep plate girders spaced on 12-ft centers with a deck widths of 37 feet. The bridge has five steel spans measuring 302 feet flanked at each end by a 60-ft precast concrete jump span. The steel superstructure permitted longer spans, reducing the number of required piers in the environmentally sensitive area below. Weathering steel girders blend well with the environment and eliminate the necessity of future painting. The four-lane Clifford Hollow steel bridge in northern West Virginia represents another highly successful use of the incremental launching technique. This 5- span 2.4-million-pound steel bridge stretches 1700 feet across Clifford Hollow, carrying traffic up to 275 feet above the valley. Crews preassembled 400-ft sections of the steel superstructure, which consisted of steel plate girders, bolts and cross-bracing. Four hydraulic cylinders powered each bridge section across the land-based track rollers on the higher abutment, forming a giant cantilever until the section reached the temporary rollers on the piers. A kingpost frame in the assembly area provided a cable-stay to the end of the bridge section.
SashaLemon
Active Member
Maybe the bridge would of lasted longer if there wasn't so much car dependent sprawl forcing people to drive across it.
innsertnamehere
Superstar
Lol what? It’s a highway bridge which is 80 years old and which it’s entire purpose is to be driven across. It’s not even like they will be demolishing it either, simply repairing it. I’m not sure any piece of infrastructure would last 80 years without rehabilitation regardless of how few cars are driving over it.
just east of the creek
Active Member
In the good old days, when it was the Kings Highways 2 and 5 that handled traffic to destinations west of Toronto, it was decided in 1934 that building a highway to handle the expanding transportation needs of the province with a population 3.5 million was required. As of 2019 the population of Ontario stood at 14.5 million and that of the GTA alone - in excess of 6.7 million. And apparently this is not enough, projections are that GTA populations will reach 7.45 million within 10 years, because in part, we have not reached our countries ’optimum’ (?!) population level - somewhere around 55 million people. Transit options are not happening quickly enough to handle that growth, car dependent transit between the growing and intensifying urban areas serviced by the QEW will continue. I can see the bridges (they are being twinned) being rehabilitated at intervals for years to come.
SashaLemon
Active Member
They should provide space for a dedicated future transit line...
just east of the creek
Active Member
Maybe. Transit improvements are needed most places. However in this instance, you are now just west of a major light rail project (Hurontario), one bridge to the south is the GO Lakeshore line, and one bridge to the north is Dundas and the potential of a BRT development. These three projects have the potential to deliver improved transit options to commuters such as myself, although I am heading for the airport area many days and that is still not automatically enticing when coming from the west of the GTA.
lexaprofessional
New Member
The Finch West LRT will help with that coming from east of Pearson, but hopefully Mississauga gets a better east-west link than the Transitway soon.
KevinT
Active Member
Thanks for digging into that! Now I wonder if the Grand River bridge on the 401 isn't being done the same way: There was a point where the new westbound span had temporary cable stays erected on it and I couldn't figure out why. Now I think it probably started out in a different position, and those held up the cantilever while it was shoved out over the river. I couldn't tell while just driving by and there was no good vantage point (except perhaps for golfers) to see it from the side. Now that I know what I'm looking for I'll pay more attention to the eastbound span's construction, and see if I can't get pictures of the shove.
drum118
Superstar
Aug 7
The drome folks need to try to get a closer look at the bridge as it hard to see it on the ground.
There are 4 girders making up a 4 section bridge with crossing bracing in place. At the west end, there are 2 sections of girders with bracing between to 2 girders that are smaller with lug holes.
Cannot see any rollers under the bridge nor hydraulic equipment to push the bridge. With lugs at the end of the 2 section temporary bridge extension. cables will come from a puller on the west side of the river to pull the bridge over the river when time comes to do it.
Crews were working on site to get ready for the next 4 girders section that should be arriving this week.
The drome folks need to try to get a closer look at the bridge as it hard to see it on the ground.
There are 4 girders making up a 4 section bridge with crossing bracing in place. At the west end, there are 2 sections of girders with bracing between to 2 girders that are smaller with lug holes.
Cannot see any rollers under the bridge nor hydraulic equipment to push the bridge. With lugs at the end of the 2 section temporary bridge extension. cables will come from a puller on the west side of the river to pull the bridge over the river when time comes to do it.
Crews were working on site to get ready for the next 4 girders section that should be arriving this week.
just east of the creek
Active Member
Drum, I would agree with you, we need some of our Drone Artists to post a flyover.
But in the meantime, are you are telling us that the four girders, make up a four section span? and this Span would connect the east side of the river bank to the easterly pier. And then the same for the westerly pier? Or do I have this all wrong?
Cheers and thanks
Tim MacDonald
Senior Member
drum118
Superstar
Tim MacDonald
Senior Member
Ok, so I dropped by the site last night. Now I remember why I don't like flying low altitude in that particular stretch; there are wires and obstructions everywhere!
Video is probably better than the photos in this case.
Some pics:
Video is probably better than the photos in this case.
Some pics: