Work on a Diverging Diamond Interchange (DDI), an innovative design and a first of its type to be built in Minnesota is taking shape on TH52 in the southeastern part of the state. Along with this project being one part of many to reach the Minnesota Department of Transportation’s (MnDOT’s) goal to make the highway a fully accessed controlled road between Rochester, Minn., and the Twin Cities 90 mi. (126 km) to the north, it is also designed to spur local development in the area.
Located in the city of Pine Island 60 mi. (96 km) south of the Twin Cities, road crews also are building a new, 12 mi. (19 km) frontage and county road system to support the expected increase in traffic as companies begin to settle in and around the interchange.
Trunk Highway 52 runs from Moorehead, Minn., at the North Dakota border through the southeastern part of the state, cutting through the heart of Rochester, home of the Mayo Clinic and continuing into Iowa.
Growing in popularity, the DDI design offers the ability to accommodate high traffic volumes, provide safe access for pedestrians and bicyclists and is less expensive to build than the typical loop and ramp design. Another DDI is scheduled for construction in the St. Cloud area of the state northwest of the Twin Cities.
With the DDI design, opposing lanes of traffic criss-cross at traffic signals at each end of the bridge crossing over the highway. This traffic design permits left turn movements without conflicting with oncoming traffic. Traffic signals, signs, pavement markings and concrete barriers guide motorists through the interchange.
Pedestrians and bicyclists will cross though the middle of the bridge on a trail guarded by concrete barriers in between the traffic lanes.
Shafer Contracting with headquarters in Shafer, Minn., grabbed the contract with a $34.6 million dollar bid to build the interchange and its’ system of auxiliary roads. Shafer is a heavy construction company specializing in grading, underground utility installation and concrete paving work.
It has more than 300 employees with an annual revenue of $90 to $100 million a year.
The interchange and its system of roads is designed to serve dual purposes. Along with building a fully access controlled interchange to eliminate dangerous, at grade crossings here, it was designed with specific industry in mind and to help stimulate additional development in the area.
“The real story here is all the agencies working together and getting out front of the development and planning all the infrastructure for the future,” said Terry Ward, MnDOT project manager.
This project was designed and submitted for bids with a promise from the city of Pine Island to add 182 jobs over the next nine yeas in the bioscience sector. An additional 200 to 300 construction jobs will be generated by this project according the MnDOT’s project Web site.
“You look at how government should deliver infrastructure; we’re delivering an interchange, a frontage road and county road system that’s all planned out for development in the future with all the local partners,” Ward said. “It maybe is the way in a text book type style that developments should be done. You know, get your infrastructure in place and have development follow versus building our [the state’s] interchange and having development build around it and then try to build our way out of that development.”
The entire project covers 5,000 acres (2023 ha) with 250 acres (101 ha) of land set aside specifically for bioscience related industry. Valued at over $3.65 million, the city of Pine Island and Tower Investments, a real estate development company backing the development donated the 250 acre (101 ha) piece of acreage for the project.
Though originally scheduled for completion later this year, the project fell victim to Minnesota’s state government shut down which halted all state work for three weeks last summer.
“The one big struggle we have is that we’re still suffering from the state government shutdown,” said Ward. “It has pushed out our completion date to 2013. We had originally planned to finish the job in November of this year. Our completion date now is September of next year so that’s kind of the dark side of the project.”
The shut down occurred when MnDOT was still acquiring right-of-way; a lengthy legal and financial process that prevented the contractor from working full steam throughout the large site and caused delays on the original construction schedule, Ward added.
On the flip side “the project itself is going fantastic,” Ward continued. “The Shafer team and their subs and their suppliers couldn’t ask for a job to go any better. In my 27 years with MnDOT, it ranks up there in terms of the partnership and working relationships.
“From that regard, the job is going extremely well. We’re engaging our local partners, the city, the county, the townships. They’ve been coming to our weekly field meetings; which is pretty neat.”
And the other part of the story, Ward said, was the long term planning for this interchange and its future impact on the local economy which fostered a business-like atmosphere and cooperative relationships between the state, county and local governments as well as with Tower Investments.
Despite the added months of construction, MnDOT had an ace in its hand with the land donation of 250 acres (101 ha) because both Tower Investments and the city of Pine Island were anxious to get the interchange in, Ward added.
“Our traditional right-of-way acquisition process is 24 months,” Ward said. “So, to make a long story short, Tower donated the 250 acres of land to the city and MnDOT took it over by a commissioners order. That allowed us to have 250 acres in our back pocket so we could start construction.”
MnDOT was dealt another ace to move this project forward on its’ construction schedule when the Greater Minnesota Interchange Fund selected this project for a $14.6 million grant award.
Combined with the land donation, “this interchange probably would not have been constructed as early as it is being done but it was selected for this grant from the Greater Minnesota Interchange fund so the committee decided it was a good opportunity to have the interchange built,” said Kristin Kammueller, community relations/public affairs coordinator of MnDOT.
To date, most of the bridge crossing TH 52 is completed and crews are now beginning to dump sub base for the 12 mi. (19 km) system of county and local roads.
To build the bridge, Shafer’s bridge contractor, Edward Kraemer and Sons, located in Burnsville, Minn., brought in a pair of American and Manitowoc 100 ton (91 t) cranes and a Delmage 19 pile hammer to hoist beams and drive the pile. Bridge construction went well, Ward said, and had minimal affect on the highway traffic below the growing structure.
“We set beams two nights in a row last September and we had some short term rolling closures but we didn’t have to detour traffic.” Ward said. As crews continued to lay the deck, Ward added, periodic lane closures became necessary yet did not create any serious traffic problems.
Because the contractor has plenty of land to work with and it is a design-build contract, flexibility has been a big part of this project’s success, Ward remarked.
“There’s a big footprint here which allowed us to have our bidders change the bridge alignment,” Ward said. “Our original concept for the highway crossing was skewed. The contractor straightened it out to make it shorter.”
It also allowed MnDOT to expand the bridge from two to four lanes “because the development is beyond what we originally planned so this interchange will have more traffic than originally planned for,” Ward explained.
At any one time, equipment shipped in to dig, scrape, grade and move material around the site included a half dozen Cat dozers and scrapers, a Steiger tractor, one Komatsu backhoe, an Ingersoll Rand vibratory roller and a Cat paddle wheel scraper.
Out of sight of the bridge but within the expansive construction site, Cat backhoes are beginning to dig trenches for the thousands of feet of stormwater pipe expected to be placed to drain the miles of new pavement poured that will be constructed on the large perimeter of roads surrounding the interchange.
“We’re putting in quite a bit of storm sewer; it’s a curb and gutter, urban type of design and we’re building a series of stormwater ponds, which is pretty common for a job of this nature. We also have some fairly good size box culverts that have to go in,” Ward said.
One wrinkle adding more cost to the fairly routine pond construction is the existing Karst conditions of the soil, which is pretty common for this part of the state, Ward noted. Because of this, “in most cases we have to line our ponds so the water doesn’t seep down into the Karst conditions and get into the water table so an option is an impervious liner that’s pretty expensive.”
The discovery of chronic wasting disease on what was formerly a 1,000 acre fenced-in elk preserve located between the highway and county road system also forced road crews to take some added steps out of the ordinary on a problem they do not usually face on a typical road construction project.
Though not affecting the construction schedule, the mitigation of the contamination required additional topsoil removal to eliminate the contaminated soil and prevent the disease from spreading.
“What we’re doing here is stripping off the topsoil and then building a fence around the contaminated soil to establish a perimeter to keep out wildlife in the infected landscape. It takes a little time and effort to coordinate all that,” Ward explained.
Eventually, the fence will come down once it has been determined that there is no possibility of any remaining contamination in the area, Ward added.
The contractor is blessed with 5,000 acres (2023 ha) of mostly unimpeded landscape to use and move around at will. With all this dirt at the door step, there has been minimal trucking activities on public roads, Ward said.
Most of the imported material is sand and aggregate for the road base. These deliveries have at times created a train of belly dumps driving into a holding area to dump the loads as Cat dozers push the sand into large mounds. What once was green, gently rolling pasture is now a temporary yet barren landscape dotted by mounds of sand piles.
Ward, who was one of MnDOT’s engineers assigned to the reconstruction of the I35W bridge on a grinding 24 hour a day, 7 days a week schedule to build a replacement within a year, is really enjoying this project.
“This one is really kind of fun because it’s a design-build, it’s not so intense schedule wise. It’s been really enjoyable to work on,” Ward remarked.
Though the summer has been excruciating hot like the rest of the country, little time has been lost to the weather. Road crews are now grading and paving a good portion of the local and county road system that circles the interchange. Meanwhile, bridge crews are completing the lighting, signing and painting on the bridge.
MnDOT and Shafer expect to have the interchange open to traffic by September 2013.
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