St. Louis shuts down aging bridge

ST. LOUIS -- A downtown artery that is actually a bridge over a tunnel has shut down for repairs over concerns about its secondary supports.

About 20,000 drivers use Tucker Boulevard daily, but many aren't aware that a section of the road is a bridge that stands above a 30-foot-tall tunnel.

Parts of the span are so corroded that the city recently shut down a block of Tucker just north of downtown. Tucker is a significant downtown artery, as well as a place for football fans to park when attending games at the Edward Jones Dome.

The street is not in danger of collapsing, said Bill Early, St. Louis bridge engineer. But secondary supports that run parallel to Tucker have weakened. Officials wanted to make sure the public was safe.

Below the bridge is a six-acre area littered with trash and used by homeless people for shelter.

The underground space was dug in the 1930s by the old Illinois Terminal Railroad for electric trains carrying passengers and freight. A nearby structure, now known as the Globe building, once served as a station for the Illinois Terminal system.

Rebuilding the bridge over the tunnel is estimated to cost $30 million, officials said. The figure likely will change once officials decide whether to rebuild the bridge or fill in the tunnel. The city plans to ask Congress for the money in the next highway reauthorization bill, which, at the earliest, would take effect in fall 2009.

For the short term, the city has requested $550,000 in federal funds to keep Tucker functional.

A sewer main runs below the tunnel, and covering it with 30 feet of dirt could cause it to collapse, city and sewer district officials said.

Buildings with foundations in the tunnel -- like the St. Louis Post-Dispatch and St. Patrick Center-- were not constructed to be surrounded by dirt. For instance, packing dirt around the St. Patrick Center, which provides services to the homeless, would block its ventilation system.

For decades, the Post-Dispatch used the tunnel to get newsprint to its presses. The last trainload was delivered in 2004, said Dennis Bennett, newsprint manager.

For the short term, about 60 shoring towers are supporting parts of the bridge where steel connections are severely corroded from the decades of water and salt that have seeped through expansion joints. The joints allow the bridge to expand and contract during temperature changes.

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Information from: St. Louis Post-Dispatch, http://www.stltoday.com