Case Study: Software Handles Highway Project's Surprises
December 20, 2010
Once Ideker removed about 10 inches of asphalt, they found that the original 1966 concrete had shifted so much they didn’t know how they could meet Missouri’s tight parameters.
Despite
tough specifications, Ideker Inc., a construction company in St. Joseph, Mo.,
recently earned a bonus of $1 million from the state of Missouri for finishing
a road resurfacing project well before the state’s
deadline.
“We had two incentives,” says Paul Ideker, president of family-owned and -run
Ideker. “One was $500,000 to complete the project before Nov. 15, and the other
was an incentive/disincentive of $20,000 per day to complete the project in 259
calendar days. We finished in 200 days.”
In December 2009, Ideker was awarded the $23 million project to resurface an
8-mile, four-lane stretch of Interstate 35 between Holt and Kearny, Mo., by the
Missouri Department of Transportation (MoDOT). Ideker already had the equipment
needed for the project. Working with Laser Specialists Inc. of Olathe, Kan.,
they had recently invested in a Gomaco 9500 Trimmer and a Gomaco 2800
four-track paver. These were augmented by Leica Geosystems PaveSmart LMGS-S 3D
machine control systems and utilized with a Cat 140H motor grader equipped with
a PowerGrade 3D machine control system.
In addition, Ideker invested in eight Leica Geosystems TPS Total Stations to
enable them to efficiently topo the whole project with three shots—the
centerline and the edge of pavements—on each of the north and south lanes every
10 feet.
But despite having all the right equipment, once Ideker removed about 10 inches
of asphalt on top of the original 1966 concrete, what they found wasn’t what
they expected.
“They had the design from when the road was originally built,” Ideker says.
“But it had shifted dramatically.”
The old 1966 pavement profile was undulating so much Ideker and his crew didn’t
know how they could meet the state’s tight parameters, which included an
overlay quantity overrun allowance of not more than 6 percent. Profile slope
changes were also required to be transitioned with a 300-foot vertical curve
minimum length.
“Concrete overlay jobs are notorious for overruns, often as high as 30 to 35
percent,” he says.
In order to get a best-fit profile—the digital data for slopes and grades—to
run the machine control software and thus the paving system to meet the specs,
Ideker turned to Brad Phipps of Applied Construction Technology, a data prep
consulting firm that the company had worked with many
times.
“I told him, ‘We need to get this done,’” Ideker says.
A Call for Help
Carlson Software helped Ideker achieve a best-fit profile on the I-35 resurfacing.
“I called the Carlson headquarters, and they came to the rescue by recognizing the need for a civil design tool to solve the problem and turned around a prototype in record time.”
“Most of the routines needed for the rehab actually already existed,” says Dave Carlson, vice president of development for Carlson Software.
“It took about two to three weeks to build on those and create what they needed.”
The main new routines developed include creating a rehab profile based on milling, leveling and overlay parameters; best-fit profile; best-fit centerline; and template grade table method to reference existing sections to set the cross slopes.
“For a concrete overlay project, the top of the finished concrete pavement is the controlling design feature,” Phipps says. “Carlson’s road rehab profile creator was used in milling mode to create a profile that was a mathematical best possible fit of the existing road surface. This profile was then used to model the proposed overlay on top of the existing road model. Quantities were then calculated and the profile was raised until the leveling quantity got close to, but did not exceed, the 6 percent overrun allowed. This step served to minimize milling quantity, which was important to the contractor.”
Getting a Good Report
“Optimizing MoDOT’s pavement structure and geometric requirements and meeting our minimum smoothness requirements while responsibly reining in the quantities was imperative for this project,” says John Donahue, construction and materials liaison engineer for MoDOT.
“Balancing all that required the tools that Carlson provided us. It removed uncertainty about the results. There was excellent coordination between all parties. The technology employed for this project eliminated the surprises and allowed us to know how it would all work before paving began.”
The paving control system that Ideker used for this project is designed to eliminate stringline, with the stringless system allowing for better and more precise control of the paver.
“Carlson Software’s contribution to the stringless paving system is the production of a geometric best-fit shape of the existing road,” Phipps says.
“To produce data of this quality by traditional CAD methods would be next to impossible, one of the big reasons concrete overlay projects have the notorious reputation of being budget busters. Carlson has now solved that problem.”
Working with Carlson resulted in tangible benefits for Ideker.
“The software allowed us to minimize the materials,” Ideker says. “… It ultimately saved us and the state a lot of money.”
Ideker Inc.
Location:
St. Joseph, Mo.
Project:
Meet tight specifications on I-35 resurfacing despite shifts in the concrete
from the original design.
Equipment Used:
Carlson Civil software
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