Collapsed pavement on Mo.’s I-470 reopens 19 days ahead of schedule

Crews sometimes worked around the clock to provide quick relief to motorists

News HNTB Corp. August 26, 2010
Printer-friendly version

Forty-three days after sliding soil triggered collapsed pavement, a restored westbound I-470 opens on Aug. 27 in the 3-Trails Crossing, 19 days ahead of schedule.

“Thanks to the extraordinary teamwork and efforts of hundreds of transportation engineers, designers and construction workers, we are re-opening this vital link 19 days earlier than the contractor’s deadline,” said MoDOT District Engineer Beth Wright. “We are also grateful to the thousands of motorists who patiently altered their routes to accommodate this emergency repair.”

General contractor Pyramid Contractors Inc. committed to re-opening I-470 by Sept. 15. Pyramid will receive an incentive payment of approximately $760,000 for restoring traffic on Aug. 27.

When MoDOT closed the busy interstate link July 17, a team composed of geologists and engineers set about the task to remedy the problem and get traffic back onto the five-lane segment of highway as soon as possible.

In the span of five weeks, workers removed the failed pavement, drilled shafts more than 60 ft deep to form concrete pillars anchored into bedrock that support the 225-ft-long bridge extension, and formed and poured a concrete deck and barrier walls. By Sunday, Aug. 22, the bridge deck was complete and then cured until the concrete was at full strength. Pyramid will continue with earthwork and grading through September. However, it will not impact the roadway.

“When we had the emergency closure of I-470 to Westbound I-435, our top priority was safely fixing the roadway as quickly as possible for the 60,000 drivers who use it every day. It took cooperation and work from many individuals to make it happen,” said Wright.

This $4.5 million project required a lot of material and labor hours to get completed in such a short time:

* The project included more than 850 tons of concrete and 135 tons of steel. This much material would fill about 10 train cars;

* 100% of the debris from the collapsed roadway will be recycled. None of the material from the old road way will make its way to landfills. Material was sorted into steel, other metal, rock and soil to be recycled or reused in other projects;

* The average work week consisted of 12- to 14-hour days—and 24 hours a day at times—7 days a week. Crews took off only one Sunday; and

* With up to 50 workers at any time this amounted to more than 20,000 hours worked on the project. If crews had worked an 8-hour day, five days a week, the project would have not been complete until the second week of October.

Overlay Init