A busy and popular four lane, east/west Twin Cities road corridor re-opened westbound lanes Nov. 16. Minnesota Department of Transportation (MnDOT) crews completely shut down Highway 36 to traffic last May and reopened a single lane in each direction on Aug. 31.
Cutting through the heart of North St. Paul, a first tier suburb of St. Paul, Minn., MnDOT closed this 2-mi. (3.2 km) stretch of TH 36 to expedite its reconstruction.
More than 40,000 commuters travel on this highway.
MnDOT awarded the $27 million contract to Progressive Contractors Inc. (PCI) located in St. Michael, Minn. PCI specializes in all aspects of concrete work including road and airport paving, sewer construction, bridge reconstruction and deck overlay.
Federal, state, county and local funds are paying for the project.
Shortly after the road closed, hundreds of road workers and dozens of pieces of heavy equipment converged to the traffic free road for a summer time “construction blitz.”
Steve Adamsky, MnDOT project engineer, said “just get in, get it done and get out of the way because that is what the majority of the public wanted.”
“MnDOT hired a marketing firm, compiled a lot of survey information and the result was that the market survey supported this concept,” Adamsky said. “Our public affairs people have met with city, business and community groups of both North St. Paul and Maplewood to keep everyone informed of the construction status.”
Though the trend across the country has been to reconstruct roads and maintain traffic; this road closure made sense to MnDOT engineers. Prime considerations they review in closing a road or keeping it open for traffic include speed, safety, cost and availability of alternate routes.
“Obviously, the work gets done quicker, the cost is a lot cheaper because you don’t have to build temporary roads and it’s certainly a lot safer for the road workers,” Adamsky explained. “The down side, of course, is the major inconvenience to the 40 to 50 thousand vehicles a day that use the road.”
“Many of the roads in the state, especially in the metro area, the traffic volumes are high enough that there are no good alternate routes nearby for detours and that’s why it’s not done too often,” Adamsky added. “In this case, we have a couple of convenient, alternate routes nearby to serve as detours.”
MnDOT routed eastbound traffic to Interstate 694 to the north. Westbound motorists are directed to Interstate 94 to the south.
Along with the road cutting through a suburban community of 12,000, small commercial properties, a 2,000 student high school and a concrete plant line both sides of the road.
According to MnDOT documents, North St. Paul officials and residents have been concerned for years because the former geometrics of the road broke up the unity of the community. The at-grade crossings of the road made access difficult for motorists and pedestrians trying to access community facilities, schools and parks located on both sides of the highway.
The crossings also were spaced close together, causing congestion during peak travel times.
The new geometrics, according to MnDOT officials, will improve safety to the traveling and pedestrian public while improving traffic flow through this relatively tight and congested segment of the road.
To reach these goals, this small road project in comparison to some of the much larger, $300 million road projects in the metro area, featured just about every construction activity imaginable.
In addition to the typical grading operations, the project included a deep, 25-ft. (7.6 m) cut lined by huge retaining walls through a good portion of the new road, four bridges, a tunnel and a sewer filtration system.
Two of the new bridges will carry east and westbound TH 36 highway traffic across McKnight Road and a third at Margaret Street, will carry local traffic across the highway.
A fourth pedestrian bridge was erected for users of the Gateway Trail, a popular pedestrian and bicycle trail near North St. Paul High School and a small tunnel will bring the same trail below Margaret Street, a busy, north south arterial crossing the highway.
Along with the filtration system, PCI workers dug five ponds to improve the water run-off from the road and better regulate water quantities.
PCI project superintendent Bill Hines noted that these features, along with a very short construction deadline, make it a “real dynamic” road project.
Shortly after construction began on the east end of the project at Century Road, excavation crews began the 25-ft. (7.6 m) cut. PCI lowered nearly a mile of the road, Hines remarked, so that “we have retaining walls up one side of the road and down the other. We’re getting the intersections out of the picture so there won’t be crossing traffic” through the area of the cut.
The new road alignment then starts coming back up just before McKnight Road, where it “flies over McKnight with two bridges” Hines added.
Here, at the center point of the project, crews lowered McKnight Road and built a diamond interchange, said Adamsky.
Now at its current grade, the new road crosses under a new bridge under construction at Margaret Street, to eliminate another busy north/south crossing of the existing highway, Adamsky added.
Once the road re-opens in late fall, commuters and travelers will see much smoother sailing than in the past. The bridges and tunnel will eliminate six at-grade crossings and auxiliary lanes will widen the highway through a good portion of the new road.
Additionally, a section of frontage road has been reconstructed alongside the new highway.
For Hines and his crew of workers and sub-contractors, the work pace has been as torrid as the unusually hot weather for this part of the country.
Wet weather early on in the project slowed the work pace a bit, Hines said. Yet, nearly four months of hot, dry conditions more than made up for the earlier wet conditions.
“You keep going if you have to finish something,” Hines remarked. “The way jobs go now, you’ve got real strict time restraints. You have to weigh what the penalties are or the damages — against not getting it done on time.”
“The contractor is on a very tight schedule to get the highway open within six months,” Adamsky added.
Supporting this schedule, MnDOT let the project as an A plus B bid letting based on bid item costs and time consumed to complete the project.
“It’s possible someone could get the job done cheaper with higher bid costs, but less time,” Adamsky explained.
MnDOT also is applying cash incentives to meet the schedule; or what MnDOT officials call a “no excuse bonus.”
“If the contractor gets the road open to one lane in each direction in 145 days, he is eligible for a $350,000 bonus which increases $75,000 for every five days previous to the 145 day deadline and up to a $650,000 maximum,” Adamsky said.
“If the contractor does not meet the deadline, we start charging $15,000 [each] day the highway remains closed after the 145 day deadline,” Adamsky added. “It’s just like the name suggests; there are no excuses for not getting the job done in 145 days.”
The long, hot summer weather helped PCI in making its first deadline when it opened the highway to one lane in each direction in August.
However, bad weather again challenged PCI workers when a stubborn, wet pattern recently pushed out the warm, sunny skies and brought in regular rains through late September into early October.
“Though the weather as of late has slowed progress a bit, overall the work is on schedule,” Adamsky said.
Along with opening the highway to one lane of traffic in each direction, McKnight Road is open to one lane each direction, the retaining walls are nearly complete, the McKnight bridges are done and the pedestrian bridge is open.
To make this all happen, PCI mobilized dozens of pieces of heavy equipment.
“We had a large group of iron out there,” remarked Hines.
A half dozen Terex and American cranes loomed above the construction site to erect the bridges and walls while Komatsu and Cat excavators tore into the ground.
Another dozen Caterpillar and John Deere dozers pushed mounds of earth around with Caterpillar scrapers and motorgraders fine tuning the finished road bed.
When construction is complete, crews will have laid 55,000 tons (55,882 t) of asphalt, placed 500,000 lbs. (226,796 kg) of steel and poured 10,000 cu. yds. (7,645 cu m) of concrete for the 70,000 sq. ft. (6,503 sq m) retaining walls.
Backhoes and trucks removed and trucked out 700,000 cu. yds. (535,188 cu m) of excavated material and sewer crews have already laid over 30,000 ft. (9,144 m) of sewer pipe.
MnDOT and its contractors are relying more on GPS technology to streamline the survey work and ratchet up production by eliminating much of the labor intensive measuring and staking required to set grades and offsets, added Duane Fobbe, PCI project superintendent.
“GPS is a godsend. Any place you want to go, you’ll get a cut of one foot or a cut of two feet,” Fobbe explained. “We’re using GPS for every aspect of the job; the road, ramps, sidewalk, walls and abutments. The only thing we’re not using it on is the pipe.”
Fobbe estimated that GPS speeds up construction surveying by 30 percent.
Every little opportunity to speed the project up helps, because the project is filled with challenges, some of them stemming from the cut itself.
“There is a lot of underground work on this project,” Hines noted. “When you change the profile that much, all of the storm sewer gets replaced and some of the sanitary.”
“When we started in April, it was real wet going. The sanitary sewer was deep and wet,” Hines remarked. “We also didn’t know how much foundation material we were going to use. We ended up using a lot of it for the large diameter pipe.”
This made staging of the sewer construction challenging and critical so “we didn’t flood ourselves out,” Hines said.
The huge excavation from the deep cuts also forced an additional 500 to 600 trucks moving in and out of the construction zone into surrounding traffic patterns, Hines said.
This additional traffic, not only in numbers but size and weight, combined with traffic detours while maintaining access to local businesses and residential neighborhoods adds to the burden of “maintaining the flow of traffic on auxiliary roads,” Hines remarked.
Because of the wet soil conditions and the clay loam underground material, PCI also constructed a unique drainage system through the area of the deep cut.
“Borings indicated that the groundwater table is higher than the final road elevation [in the area of the cut],” Adamsky explained.
To control the extra water, the contractor installed a “blanket” through a half mile section of the cut, Adamsky added.
It consists of a geotextile fabric on the ground, with 12 in. (12 cm) of rock on top of the fabric, topped off with another fabric and 3 ft. (.9 m) of sand.
“All this is connected to a mini storm system to a manhole that drains off the job,” Adamsky explained. “By permit, we need to monitor the volume of water leaving the job with computerized monitoring devices located in the manhole.”
“This is unique to this job. You don’t see this in every road project,” Hines explained.
Despite some delays caused by the recent wet weather, the construction is mostly on schedule.
PCI made good progress on the remaining paving and bridge work, Adamsky said and had the road open in November as originally scheduled. PCI collected most, if not all, of its cash incentives, he added.
Final completion of the entire project is slated for the fall of 2008. CEG