Ontario isn’t promising a bridge wheelie, but there should be enough excitement to go around on Aug. 11.
That is when the Island Park Drive bridges over the Queensway will be replaced in just 15 hours. Using a new technology to North America, the old spans will be cut and moved for new and improved sections with minimal disruption to traffic.
“We are definitely very, very excited about this because it is something new to us,” Frank Vanderlaan, senior project manager for the Ontario Ministry of Transportation, told Roads & Bridges.
Ontario will bring out about 20 self-propelled modular transporters (SPMT) to handle the switch from yesterday’s bridge to tomorrow’s. The transporters consist of anywhere between four and six axles and are basically made up of rubber tires, according to Vanderlaan. Each wheel is able to turn on its own axis, which means they can come as close to turning on a dime as any device carrying 500 tons. An operator controls movement with a joystick.
“It’s so versatile,” said Vanderlaan. “It can come right down to the millimeter. It is almost like a flatbed with a bunch of wheels.”
Vanderlaan said because so many axles are involved, the heavy weight of the bridge is spread out over the entire surface, so the impact on the road is the same as one produced by a heavily loaded semitrailer.
Prep work has been going on for several weeks now. The new bridge deck, which will be about 25 meters long and carry eight lanes of traffic, is being built in a parkway adjacent to the Queensway. Work on the existing structure consists of saw-cutting the top portion of the ballast wall, which will allow the SPMTs to essentially lift and move the segment. The saw-cutting has required the contractor to execute some lane closures, particularly on the weekends. When the existing deck is removed, the SPMTs will place the new deck on new bearing plates.
“As soon as the existing span is carried away, crews will go in there and set these new plates,” said Vanderlaan. “There will be some leveling and adjustments to be made, and that will take a long time to make sure everything is perfect.”
The entire move can be seen via a web-cam on www.417queenswaybridges.ca.
Refacing of the abutments, wing walls and the installation of a new 200-mm-thick concrete wall also will take place. New approaches will be built and the bridge deck will receive a new coat of asphalt.
“At the end of the day the whole structure will be completely new.”
Since the road will be closed for 15 hours Aug. 11-12, the Ontario Ministry of Transportation has taken aggressive steps in informing the public about detour routes. Public involvement centers have been formed, an ad will be placed in local newspapers and, according to Vanderlaan, it has been picked up by the local TV media.
When it is all said and done, the SPMT technique is expected to save Ontario $2.4 million and as much as two years time. Four more bridges along the corridor will experience the same move in the coming months, making the SPMT technique a standard procedure in a country that is feeling the effects of an aging infrastructure much like its U.S. neighbors.
“Most bridges are 50 years old and are in need of replacement or major rehab over the next two years,” said Vanderlaan.
