[画像:Bill Emerson Memorial Bridge]
Building cable stayed bridges is pretty much a cookie-cutter science these days. As a result, the bridge was built with few problems. The biggest issue was fissures found in the bedrock under one of the towers. The original contractor was in over their heads, and a new contractor had to be brought in to solve the problem and complete the bridge. The solution to the fissure problem was to jet-grout concrete into the cracks. Later, a major flood threatened progress. The contractor feared that the caisson on the Missouri side would be overtopped and flood. To beat the flood, they poured 4,700 cubic yards of concrete in around the clock shifts. As it turned out, the concrete was complete before the river flooded. Had they not pushed the pour, it would have set the project back more than two months to wait for the river to go back down and to pump out the caisson.
The road deck is made out of a concrete mixed with silica fume, made from silicon metal. This is supposed to give the deck a 50 year lifespan.
Bill Emerson served in the House of Representatives from 1980 until 1996, when he lost his battle with lung cancer. Emerson served on the Public Works and Transportation committees, and was instrumental in getting this bridge approved.
This bridge replaced an older multi-span truss bridge, which was closed and removed once the new cable stayed bridge opened. As the main spans of the old bridge were imploded, two more spans of the bridge unexpectedly collapsed and fell into the Mississippi River.
