Client: Flatiron/Manson, Joint Venture
Contract Value: $240 Million
Description: Geometry Control and Survey Oversight for I35-W Bridge Replacement

On August 1st, 2007, the tragic collapse of the I35-W Bridge over the Mississippi River in Minneapolis initiated a rapid series of events culminating in the completion of the new Saint Anthony Falls Bridge on September 18th, 2008. This extraordinary feat was accomplished by a joint venture of Flatiron Constructors and Manson Construction Company who retained the services of Civil Geometrics at the start of construction in November of 2007.

Our immediate task was the development of formwork geometry for the precast segments – a task that we completed just in time for carpenters and several weeks before the designer provided geometry for this purpose. As work progressed, our involvement expanded to include geometry control and survey guidance for virtually every aspect of the project’s superstructure including:

• Ground control survey planning and analysis
• Cambered digital terrain model development for cast-in-place soffits and decks.
• Development of highly precise segmental as-cast survey procedures that did not require the usual survey towers (It was deemed impractical to use traditional methods in the harsh Minnesota winters.)
• Calculations and oversight of erection control and tracking surveys.

As a significant participant in the St. Anthony Falls bridge replacement from start to finish, Civil Geometrics played a vital role in the successful completion of this high-profile project three months ahead of schedule.