Just before Christmas, David, Tim, and Nathan joined Dr. Ronaldo Luna and his graduate student, Devin Dixon, of Missouri University of Science and Technology (formerly the University of Missouri–Rolla) to conduct a live load test on the all but officially complete Foothills Parkway Bridge No. 2., near Pigeon Forge, Tennessee. During installation of the micropile foundations, DBA and Dr. Luna’s research team installed strain gages in four micropiles and at the base of the pier pedestals at both Piers 1 and 2 of the bridge. Strain data have been collected during construction of the superstructure. Following completion of the bridge, the live load test involved loading the bridge with four loaded dump trucks at prescribed locations with respect to the instrumented piers. Data were collected for several load configurations. The aim of the research is to better understand the performance of micropiles and micropile groups, particularly with respect to bending.
Visiting the site for the load test provided an opportunity to take some great pictures of this particularly scenic bridge nestled in the foothills of the Smoky Mountains. A new web album of pictures taken by David has been added to our Picasa page here, and some aerial photos of the nearly completed bridge taken in December by Aerial Innovations have been added to our Picasa web album Foothills Parkway Bridge No. 2 – From a Bird’s Eye View.
The new I-70 bridge over the Mississippi River near St. Louis, Missouri is quite the project. When completed, it will be the third longest cable-stayed bridge in the United States, with a 1,500-ft main span. Most significantly for the geotechnical community, the bridge made history when one of its 11-ft diameter drilled shafts resisted a world record breaking 36,000 tons (bi-directional) during an O-cell load test. The bridge has already seen press in Civil Engineering Magazine(July 2010, page 30-32), at ENR.com, and in a post by Robert on this blog. Now, an article by DBA’s Paul Axtell is featured in the September/October issue of Foundation Drilling Magazine. The editor summarized the article saying:
The information in the following article is a composite of material that came to Foundation Drilling Magazine from three separate sources. Part I is based on information gleaned from an article that was published on the Associated Press news wire. Part II is excerpted from ENR’s August 18th, E-Newsletter. Part III was provided by Paul Axtell and Dan Brown of ADSC Technical Affiliate company, Dan Brown and Associates. The bridge project is of interest in general. The Osterberg Load Cell test will be of particular interest to professionals in the deep foundation industry, and specifically for those who work in the drilled shaft segment.