Wednesday, June 1, 2011

Safe & Sound Bridge Program Reaches Halfway Milestone

Fourteen new bridges opened to traffic last week, pushing the number of completed Safe & Sound Bridge Improvement Program projects past the halfway point.

There are now 410 new or rehabilitated bridges that have been constructed all over the state, and on average, another is opening every two days. When completed, the Safe & Sound program will have repaired or replaced 802 of the state's lowest rated bridges. Just this year alone, 80 new bridges have been built.

The program's original goal was to complete 802 projects in five years, or by the end of 2013. At the current rapid pace, the program should be complete a full year early, or by the close of 2012.

So far, 231 new bridges have been constructed under MoDOT's design-build contract with KTU Constructors, and 179 bridges have been rehabilitated through the department's regular monthly lettings.

The average road closure associated with the Safe & Sound projects has been 40 days, or about half the time it normally takes to replace a bridge.

Currently 77 bridges are under construction, with another 12 scheduled to start next week.

Making Impossible, Possible

Moving something that weighs four million pounds seems impossible. Now imagine the four million pound object is 670 feet long and 55 feet above the Gasconade River. Well, MoDOT likes to make the impossible… possible.

The westbound lanes of the I-44 Gasconade River Bridge needed to be replaced and so to minimize motorist impact, MoDOT utilized an innovative method of bridge construction called bridge jacking. This method includes building a new bridge deck on a temporary substructure right next to the existing bridge, and when the new bridge deck is finished, sliding the new addition into place using hydraulics.

This amazing feat closed the westbound lanes of the I-44 Gasconade River Bridge for just 19 days, while traditional bridge reconstruction methods would have closed this same stretch for at least 60 days. Talk about a traffic headache reduction!