Photo courtesy of the N.C. Department of Transportation
The crews building the new I-85 bridges over the Yadkin River are getting a helping hand from the platforms, or “fingers,” that extend out from the temporary work bridge.
Just after World War I, a young soldier named Dwight Eisenhower never forgot his long, dusty and monotonous experience of crossing the country by vehicle convoy on the rough roads of those days. The trip took weeks. When he became president, he pressed hard for a national interstate system.
In its infancy back in the 1950s, much of the emphasis for the interstate system was on the increased speed it would provide. Over the years travelers could add simplicity of travel to the list of the benefits of this tremendous transport system and aside from speed and convenience, safety as well.
But one stretch of Interstate 85 through North Carolina as it reaches and crosses the Yadkin River for years found itself with a much higher crash rate than the statewide average crash rate for comparable facilities. Sixty thousand to 70,000 vehicles per day pass through this busy corridor.
A $136 million bridge and road building project is under way that will make this stretch safer.
“Dating back to 1955, the current bridge, though a straight span crossing the river, lies between two curves that were not designed for the heavy traffic that uses the road today,” explained Adam Mathews, project manager of Flatiron-Lane, the main contractor on the job.
“The curves on either side of the river are fairly sharp and the span is only two lanes on each side of the interstate. When completed, the three miles of highway will have four lanes on each span and the approaches will be much less problematic. The new bridges will start about 500 feet east of the current location.”
Two of the cranes used for the project are owned by Flatiron-Lane, and were brought onto the site from various parts of the country and the world. They are currently using seven track-mounted cranes: four Manitowoc 888’s, two Manitowoc 4100’s and one Manitowoc 555. The 4100s have yellow drill attachments on them. These Manitowoc cranes are of various ages.
The tallest has a height of about 180 ft. (54.8 m). Some of the cranes have attachments for drilling and drilling has been done down to the bedrock, some 70 to 80 ft. (21 to 24 m). Three cranes are involved in that. The shafts being drilled on the land side are actually deeper than those in the riverbed, as on the land there is more soil before the rock is reached. In the riverbed more erosion of the soil has taken place and the bedrock is closer to the surface. Another crane is at the lay down yard where the rebar cages are located.
Each crane has its own operator and around all these cranes some 50 to 60 people are typically busy at work. There are two 888 Manitowoc cranes and many workers assembling the trestle ahead of the bridgework.
Most of the crane work is on schedule. Though it was a rough winter, it hasn’t really been too bad for getting the work done, according to Mathews. At one point work had to shut down due to too much rain and the soil being unable to dry out. Protecting the wetlands here also has been something of a challenge.
“North Carolina is a very environmentally conscious state,” said Mathews. “There were also a couple of days when we had to take cranes down due to the high winds, but that is also nothing out of the ordinary on such projects as this.”
Darin Waller, resident engineer with North Carolina Department of Transportation (NCDOT) has been involved in administering projects to make sure they are built to the standards and the specifications, to keep track of any material testing on the site and sampling the concrete and the soils.
“NCDOT has about ten people on the Yadkin River highway job. Once the construction season gets ready to start ramping up, we’ll probably have 20 to 25 people out here,” Waller said.
A temporary bridge is being built so that they can access it to build the two permanent bridges over the Yadkin River. The main bridges are almost 3,000 feet in length.
“A long bridge is necessary because basically we’re in an environmentally sensitive area, spanning the wetlands, and we had to keep from damaging those and trying to have as minimal an impact on that area as possible. In this project not only do we have the environmental concerns that we’ve got to address, but we also have to cross the railroad twice,” said Waller.
One of those crossings is spur line and the other is a mainline track for North Carolina Railroad and Norfolk Southern, the operating railroads on that line. This is a fairly busy track, according to Waller, because several miles just north of the track is one of their switching yards.
West of this work, upstream of the project, stands a historic concrete arch bridge called the Wilcox Bridge. Repair work is being done to that structure and when they are done with that bridge, there won’t be any permanent traffic on that span. It will be turned over to Davidson County for use as a walking bridge for pedestrian traffic.
Paralleling the Wilcox Bridge is the US 29/70 bridge which also is going to be replaced during the Yadkin River project. Flatiron-Lane will be building the U.S. 29/70 northbound bridge using each completed section of the bridge as the work platform for the next section; eliminating the need for a temporary work bridge and reducing the impact to the environment. NCDOT has three bridges all within a short distance of each other that it also is working on at the same time in this corridor.
Work on the Yadkin River project started in October 2010. The plan is to have traffic on the first northbound bridge of I-85 by March 2012 and all traffic off of the old bridges by May 2012, and by January of 2013 Flatiron-Lane will have the entire project completed.
“That is a very fast pace to build a project of this size in two and a half years,” said Waller.
This is a design build project, in which teams of designers and contractors work simultaneously to design and construct a project to speed up completion. This approach helps avoid cost inflation on longer projects and allows the contractor to make innovations that save taxpayer dollars, according to Waller.
Flatiron-Lane is a joint venture of Flatiron Constructors Inc., based in Longmont, Colo., and The Lane Construction Corp., Cheshire, Conn. The partnership submitted a bid far less than the anticipated $180 million cost for the construction. STV is doing the design work of the bridge.
Another section just north of this one is getting ready to start up. That work will go from the end of this project up to the point where Business I-85 splits in Linwood, N.C.
“Once that project is done it will pretty much complete this corridor in this area, involving the widening,” added Waller.
Besides environmentally sensitive areas, there are historic lands in the immediate vicinity as well. An old trading ford is in the area where the river was once crossed, perhaps by ferry. York Hill, a battleground, is located near the historic bridge.
“A wide variety of agencies had to be met with in our efforts to get a design of the bridge that everyone could be happy with, another challenge going into this project and letting it get under way,” said Waller. “We wanted to make sure our design and everything we do satisfied everybody.”
In addition to replacing the I-85 bridges spanning the Yadkin, the U.S. 29/70 bridge and the parallel bridges that cross over the North Carolina Railroad tracks north of the river, phase one plans also include: replacing the parallel bridges over the Duke Power Industrial Rail Spur south of river; reconstructing the interchange of I-85 at N.C. 150; removing the interchange of I-85 at Clark Road and the construction of noise walls.
Work is being done 24 hours a day. Flatiron-Lane is making a concerted effort to minimize disruption to I-85 traffic, improve safety when hauling materials and equipment to the construction sites; and constructing a single temporary work bridge instead of two separate temporary work bridges when replacing the I-85 bridge over the Yadkin River. Doing so is more environmentally friendly and will accelerate the work schedule. Flatiron-Lane also is providing a five-year warranty on the project.
The new bridge has spurred interest from all around the state, where it’s considered the number one project right now, according to Mathews.
“The governor and the Secretary of Transportation have both visited the project, as have quite a few others. We’re glad that the Flatiron-Lane crews, cranes and equipment are all part of that process.” CEG