GPS technology was put to good use on the muck pockets to guide the operators to stable ground.
(Dick Rohland photo)
Surrounded by the rolling farm and prairie land of central Minnesota, road crews are months into an ambitious highway improvement project to widen a 9-mi. section of highway from two to four lanes.
This is the first of a two-bid project to add capacity over a 16-mi. section of Hwy-23 between the Minnesota communities of New London and Paynseville located just west of St. Cloud, Minn.
The second bid will be let in December 2022 to complete the remaining 7 mi. of road.
The total segment of 16 mi. of highway is the only section of road still carrying two traffic lanes between Willmar in west central Minnesota and I-94.
Through this section of highway, four lanes turn to two then back to four lanes. Minnesota Department of Transportation (MnDOT) staff dubbed the three-year project the "Gaps" because of this lane inconsistency.
The work now taking place is called the North Gap of Hwy-23. The second half of the project will overlap this years' project when equipment and labor mobilize in the spring of 2023 for the South Gap.
The two projects combined have an estimated price tag of $101 million with funding coming from the Corridors of Commerce program.
Mathiowetz Construction based in Sleepy Eye, Minn., won the first contract of this two-part project with a $41.75 million bid to rebuild the North Gap section of road.
Now in its fourth generation of this family run business, Mathiowetz Construction has years of experience working with MnDOT and is known for its services in site work, grading, aggregate and trucking, GPS services, demolitions, heavy hauling and drainage.
Knife River Corporation, located in 14 states, is the paving contractor on this project.
This road improvement construction is a combination of completely new pavement for the westbound lanes and a mill and overlay with new shoulders throughout the eastbound lanes.
Work began last January grubbing and clearing trees. Crews removed 35 acres plus 500 additional trees and recycled them. They saved 75 of them, leaving 10 to 12 ft. of the trunks and root systems intact.
Called "root wads," they have been implanted into a stream embankment for support and erosion control. The remaining trees were chipped and saved for further erosion control efforts.
The hot spot through most of the construction season this year is occurring through the first 4 mi. at the east end of the project.
It is here that the existing pavement winds through a series of small lakes called the Chain of Lakes. The stream runs north and south and crosses under this section of highway four times.
It is this piece of the project that is defined more by the weak soils and tons of excavation activities then the final product itself.
Several pockets of muck ranging from 15 ft. to more than 60 ft. deep are scattered throughout the work zone. These all need to be excavated and stabilized before any pavement can be laid.
"Construction has been going well. It's not a sprint but more of a marathon. It takes a lot of planning and scheduling, but we have a great team that does quality work while getting us to the finish line on time," said Greg Huiras, Mathiowetz construction manager.
Working to the advantage of crews, this section of existing road has been shut down to through traffic with just a trickling of local traffic running through the work zone. A detour winding around the north side of the project is set up for through traffic.
For the 50 heavy equipment operators now working the project, it's as close as they can get to operating their Cat backhoes, dozers and scrapers and a few pieces of Volvo equipment in a giant sandbox that stretches for miles beyond their eyes.
But this is not play; it's work. And work it is as equipment operators this year are in perpetual motion to dig out nearly 200,000 cu. yds. of muck, push sand back in to build up and strengthen the weak sub soils and grade the road-base to carry two more lanes of traffic.
Through the early weeks of summer, operators behind the controls of several Cat backhoes have been digging out pockets while Cat scrapers run in circles picking up and dumping clean fill back into these areas.
"We have several muck pockets that need to be removed, then backfilled with sand," he said. "The stream crosses under the road four times so we have four box culverts to place. The culverts are 300 feet long and some have double strings. We remove all the embankment again, get down to the flow line of the stream, install the culverts and place the embankment to finish grade and ready for pavement."
In what Huiras calls a rolling surcharge, backhoe operators reach down 35 ft. deep with the bucket, dig out the muck then dozers push sand back in.
Andy Huiras, Mathiowetz construction supervisor explained that MnDOT has set elevations in the plan and all the backhoes are equipped with GPS to guide operators to the required depth.
One pocket is 65 ft. deep and in an environmental sensitive area bordered by wetland.
"We can't just muck it out because the wetland next to it would cave in," he said. "We're placing a working platform over the top of the muck that includes three to four feet of wood chips saved from recycled trees, then fabric and a surcharge of sand. Then, crews are placing wick drains to pull out the water."
All pockets are electronically monitored throughout the settlement periods to ensure the surcharge hits more solid geological conditions.
The stream was temporarily diverted in May to allow crews to install the box culverts under dry conditions. However, monsoon like rains moved in and deluged this part of the state to make things more interesting for the crews.
"We had to divert the stream, and this is when we placed the root wads along the banks," said Greg Huiras. "As we were doing that, we were hit with six inches of rain in a two-day period."
Utility removals and relocations were finished in early June.
"We have three major fiber lines, and the Stearns County Power Company overhead line in this road. We had all of them moved ahead of schedule including a 2.5-mi. open trench gas dig to remove the existing high pressure steel gas main and replace it. That was the biggest hurdle to jump early on," Huiras said.
Typically, Mathiowetz Construction brings back a total of 150 people to work construction sites during the peak of the season.
And for Greg Huiras, it is one of the most rewarding parts of his work.
"We bring back a lot of veterans. We hire a lot of great men and women. It's always fun to work with new people and train and see them do well. That's what we're all about. We like training and retaining employees," he said.
For Andy Huiras, two items stand out on this project.
"It's a pretty aggressive schedule to get everything paved up and make the traffic switches and then the rolling surcharges. It's something we haven't done before so it's our first go around at it," he said.
Quantities on this project include 120,000 tons of asphalt; 17,000 ft. of sewer and pipe; 1.7 cu. yds. of common excavation; 1,400 ft. of precast box culvert; and 100,000 cu. yds. of aggregate.
Mathiowetz crews have a mechanic with a fully equipped repair truck on its construction sites with the ability to make most repairs if necessary.
Except in some of the surcharge areas, the new westbound pavement will be done by Nov. 1. All traffic will be switched to the new alignment and the eastbound lanes will be shut down over the winter.
This coming spring, mill and overlay work on the eastbound lanes will start up as the South Gap of the project begins work.
This seasons' highway work will open to all four lanes of traffic in the fall of 2023 and the South Gap section of the project will be completed in the fall of 2024. CEG
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