(AP) - Construction starts Thursday to replace the Minneapolis freeway bridge that collapsed almost three months ago.
Flatiron Constructors of Colorado, the lead contractor, faces a Christmas 2008 deadline to finish the bridge or face penalties from the Minnesota Department of Transportation. Flatiron pledged to finish the $234 million replacement bridge in 437 days, a countdown that began Oct. 15.
When finished, the bridge will rise 115 feet above the Mississippi River and contain 48,700 cubic yards of concrete and almost 22 million pounds of steel.
The construction schedule includes about 900 items on desk-sized pages, spread over the desk of MnDOT project manager Jon Chiglo, who is occupying a temporary office near the construction site on the Minneapolis riverfront.
Work will start on each bank of the Mississippi River, with the center span the last piece of construction.
Crews will start by drilling at least 100 feet into the ground to build a test shaft, lined with steel and filled with concrete. If the shaft withstands hydraulic pressure, work will start on the bridge's 32 shafts. The test shaft won't be part of the actual bridge.
The bridge's piers were located to avoid storm drains, underground utilities, a railroad track, a dumping ground for river dredge spoils and a covered polluted site under the southern approach.
Most construction can go on during the winter months, and crews will try to limit noise by working mostly during daylight hours, MnDOT spokesman Kevin Gutknecht said. The city of Minneapolis hasn't received a request from contractors to work at night, city spokesman Casper Hill said.
(Copyright 2007 by The Associated Press. All Rights Reserved.)