In July, the Northeast Anthony Henday Project, the final leg of the new ring road around Edmonton, Alberta, reached its halfway point.
The massive project includes the construction of 17 miles of six- and eight-lane divided roadway and 47 bridge structures, including 37 highway bridges and interchanges, eight rail bridges and two bridges over the North Saskatchewan River. Crews will use 100,000 cu meters of concrete, drive 90,000 linear meters of pile and move 16 million cu meters of earth to complete the job. It is the largest ever transportation project undertaken in the province of Alberta.
Sections of the ring road were built in the 1970s and 1990s, with the current Anthony Henday Drive project beginning in the 2000s with the construction of the southwest section.
The project is a public-private partnership (P3), an innovative financing and project-delivery structure under which the private sector assumes a major share of risk and financing for public-sector infrastructure. Under a P3 contract, infrastructure is usually designed, constructed, financed, operated and maintained—typically for several decades—by companies from the private sector. For the Northeast Anthony Henday (NEAH) project, the owner, the province of Alberta, contracted Capital City Link General Partnership as the concessionaire to design, build, finance, operate and maintain the construction of NEAH. The project is being designed and constructed by a joint venture team of Flatiron, Dragados, Aecon and Lafarge (FDAL). Using the P3 process, FDAL will finish the final link of the ring road an estimated three years earlier than with a conventional delivery method.
As one of the largest transportation P3 contractors in North America, lead construction joint venture partner Flatiron is one of only a few contractors with a proven record of successful P3 project completion. Flatiron also built the Northwest Anthony Henday Drive project, another segment of the larger ring road project. Plus, Flatiron also is only one of a handful of contractors delivering P3 transportation projects in the U.S. In California, Flatiron is the lead design-build contractor for the Presidio Parkway project replacing the aging approach to the Golden Gate Bridge.
“As far as comparing a PPP to a design-build, it is very similar in the approach,” said Flatiron’s Rob Richardson, structures manager on the project. “It’s different, definitely, because you’re not just looking at a transportation or government entity for ownership of the project. There’s a design review by both parties, but we’re building to Alberta Transportation standards, and that’s what we’re judged against.”
Building the northwest leg of the Anthony Henday project helped the current team hit the ground running on this segment.
“Flatiron perfected our approach on the Northwest Anthony Henday project,” said Richardson. “Because Flatiron had executed a plan that worked on the northwest leg, we didn’t have to mess around second-guessing or trying things on this job.”
NEAH is a scaled-up version of the earlier northwest job. This project is more than double the size of the earlier project, completed in 2011, both in number of structures and length. Flatiron also built the Northeast Stoney Trail project, a P3 ring road around Calgary, with Alberta Transportation.
“These jobs gave us a chance to better know the owner, and vice versa,” said Richardson. “They’re evolving, as well. There have been lessons learned on both sides.”
FDAL has divided the project into five segments, and much of it is being self-performed by the joint-venture team.
“We’re self-performing most of the work including earthworks and drainage in three of the five segments and all of the pile driving, cast-in-place concrete work, girder erection, concrete placement and wall construction.”
The FDAL joint-venture construction team is co-located at a project office in Edmonton, where they work together to facilitate work on 18 different sites. On any given day, crews are performing work that varies from underground utility jobs to construction of multilevel flyovers. The job is massive not just in scope, but it also covers a large area, spanning about 20 kilometers from north to south and about 8 kilometers east to west.
“It’s the scale of it that gets to be the challenge. It’s similar to a regular job, but on steroids,” said Richardson. “We do have a basic division of scope management between earthworks and structures. We struggle just like every transportation project does to keep both sides coordinated. That’s the main role of the project manager—to see the big picture—but we’re all always trying to step away from our individual scopes and look at the bigger picture, too.”
The size of the job presents many challenges, including variable weather from one end of the project to the other. But in June 2013, the area experienced heavy rainfall and flooding that affected the entire province. The provincial government described it as the worst in Alberta’s history. The most significant impact on the NEAH project was at the North Saskatchewan River. The temporary berm installed to facilitate constructing the two river bridges was designed using historical data for the river water elevations, but the water levels during this flood event had never been seen before and the berm was overstepped, flooding the work area with 20 ft of flowing water. Crews worked around the clock for five weeks to get back on schedule and maintain progress at the two largest structures on the project.
Summer season rains also affected numerous earthworks operations that the team tirelessly worked to get back on track, including culvert installation, utility installations and relocations and roadway construction as well as mechanically stabilized earth (MSE) wall construction.
Getting back on track is even more critical in Edmonton’s northern climate, where winter can be brutally cold, with temperatures dipping down to −22°F with the wind chill, shutting down earthwork operations and making drainage and structures work difficult and expensive to perform through the winter months.
“The weather definitely impacts what we do,” explained Richardson. “Our work is very seasonal, and there are certain scopes of work that you have to get done in certain seasons or it doesn’t get done for six months. So in the summer you’re focused on all your earthworks efforts—moving dirt, building MSE walls, grading—and you work the structures scope in such staging that you stay ahead and out of the way of the dirt guys as much as possible.
“In the off-season, we’re pile driving, and any concrete pours we make we have to artificially heat. It’s called heating and hoarding. Hoarding is the means of encapsulating the element with tarps. We then blow heat into the hoarding to keep the concrete-pouring and curing environment warm. We try and minimize it, but we still end up doing some. You can’t put off everything and only do what’s convenient.”
The structures crew has to ensure that by the time the next summer season rolls around, they have their work complete to allow the subsequent earthwork phase to begin. In the summer of 2014 alone, crews will move 5 million cu meters of dirt and have 40 different bridge sites under construction. If bridges are not done to the appropriate stage, gaps are generated, which result in inefficiencies and schedule delays.
To create even more construction efficiencies despite the cold weather, the team is using a precast-deck-panel method of bridge deck construction. The precast deck panels serve as a concrete formwork, which can be cast and installed in winter or summer. The method reduces the temporary deck formwork required, taking pressure off of a stripping and forming operation that would be required using conventional means.
“It’s kind of a two-stage bridge deck,” said Richardson. “Our concrete formwork is actually a concrete panel that is precast, delivered to the site and then set on top of the girders. Rebar is installed on top, and then we make a second pour.”
The method represents additional time savings and resource efficiency, because it allows for concurrent construction of multiple structures—critical on a job with 47 bridges.
“If we formed all the bridge decks conventionally, we would have to cycle the same forms from bridge deck to bridge deck. We can form precast panels indoors all winter and put them up as we go, and are not limited by forming resources,” said Richardson. “So we are spending a little bit more money at the end of the day to a precast supplier, but we get a significant time savings overall and a production rate gain because the bridge deck comes together much faster.”
In all, crews will construct 15 steel girder bridges, 23 precast NU girder bridges and eight precast concrete-box-girder bridges.
300 of 500
Utility relocations and crossings within the NEAH Transportation and Utility Corridor have been one of the most strenuously pursued scopes, due to the schedule impacts that surfaced. There are more than 500 existing utility obstacles on the site, and crews will have to relocate and/or protect nearly 300. The entire team has had to work together to come up with innovative designs and traffic-accommodation strategies to ensure that the utility delays do not stand in the way of the project’s opening to traffic in October 2016.
“Utilities have been a huge challenge,” explained Richardson. “Oil from the Oil Sands region in northern Alberta is piped to refineries and gas facilities adjacent to the project. There are pipelines everywhere, intertwined among the existing infrastructure. We designed most of the structures to avoid them. But there were some where this was not possible, which resulted in lengthy relocation processes. Even to work in proximity to a pipeline or to cross one with an embankment has its challenges. Permits are necessary, which often require engineered analyses to assure pipeline integrity during and after construction, and this requires close working relationships with the various pipeline owners.”
The team also is dealing with more traditional utility relocation work, such as power transmission, telecommunications, water supply, storm drains and sanitary sewer.
Shaping up to grow
Despite these challenges, two years in, the project is starting to take shape. Major earthworks hauling is complete in two of the five project segments, gravel base placement and paving has started in several areas and 15 of the 47 bridge decks have been poured.
Once complete, the entire Anthony Henday Drive, including already completed segments, will be the first free-flowing ring road in Canada, and an estimated 40,000 motorists will use it on a daily basis. The new road will give people a continuous route around the city, and will help relieve congestion on other city roadways.
“The project itself is very forward-thinking in terms of anticipating growth,” said Richardson. “The owner is doing a good job at staying ahead of the growth curve instead of trying to react to it, which is something that we could learn from in parts of the U.S.” R&B