|Gene Smania comment on Bridge Hunter, Mar 2004|
The Lincoln bridge is a conventional tied-arch design. It uses a large steel arch with suspension cables to support the roadway over the main span, which is 620 feet in this case. The arch is flanked by over a mile of steel girder bridge that is elevated about 60 feet above the river valley. The approaches are built as two independent bridge spans, but they join into one bridge span to cross the main river channel.
At the time the bridge was built, the contractors requested and were granted permission to take a short-cut by not removing the wood that was used as concrete forms when installing the concrete deck. This decision turned out to dramatically shorten the life of the structure. The wood held water, and caused key steel connections to rust, and it caused the concrete to rot. By the mid-2000s, the only choice was to strip the bridge down to it girders and rebuild the traffic decks. The net result is a $30-million repair bill for a bridge that is less than 20 years old.[John Weeks]
These two photos not only capture the repair work that was done but show how most of the bridge goes over a backwater rather than the channel itself.
[Look how much concrete they had to remove for a patch on the northbound pier.]
Ron Faizer posted two photos with the comment: "I-39 crossing the backwaters of the Illinois River at LaSalle-Peru. Shot with a DJI Phantom 3se camera drone."
[This also emphasizes how long the bridge was south of the channel.]
|Linda Brown, Jul 2019|
Lloyd Scott Hardin posted four photos with the comment: "Illinois river LaSalle upper bridge 12 pack for Lemont."
I learned about the Gwyneth Anne just a few hours ago while studying a photo in Joliet.