Very carefully, of course! (You knew that was coming!)
DBA has had the pleasure of consulting with Sundt Construction on their effort to replace the West 7th Street Bridge over the Trinity River in Fort Worth, Texas. Our role has been to provide geotechnical consulting for the heavy lifts of the arches, as well as a VE design on a secant wall.
The aging Seventh Street Bridge, a popular east-west thoroughfare that connects downtown to the Cultural District, is due to be reconstructed.
The original span was built in 1913 and was expanded in 1953 when the Trinity River was rerouted and the surrounding levees were built. Although the bridge has been determined safe to use, beams, girders and the deck of the 1913 section are deteriorating.
To reduce the impact of closing the bridge, Sundt has installed new drilled shaft foundations on either side of the existing bridge. The twelve, 163-foot long, 300-ton concrete arches were fabricated off-site on the west side of the river. Large trailer dollies with 120 wheels move the arches from the yard to the site. Large cranes from Burkhalter (heavy lift and transport specialist) pick the arches from the dollies on the existing bridge and set them on the new foundations. The bridge is closed or partially closed during each lift. Once all of the arches are in place, the bridge will be closed to demolish the existing structure and build the new deck between the pairs of arches. The compete closure is supposed to last only 150 days.
Here is a time lapse video of the first arch being set:
The first arches were set over the weekend of May 11-12. Here are some links to video and articles:
TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 380: Guidelines for Geofoam Applications in Slope Stability Projects explores the use of expanded polystyrene-block geofoam for slope stabilization projects. For the purpose of the report, slope stabilization projects include new roadways as well as repair of existing roadways that have been damaged by slope instability or slope movement.
The research was performed by the Department of Civil Engineering at The University of Memphis (UoM). David Arellano, Associate Professor of Civil Engineering at UoM, was the Project Director. The other project investigators were Timothy D. Stark, Professor and Consulting Engineer, Department of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign; John S. Horvath, Consulting Engineer and Professor, Civil and Environmental Engineering Department at Manhattan College; and Dov Leshchinsky, President of ADAMA Engineering, Inc., and Professor, Department of Civil and Environmental Engineering at the University of Delaware.
This report presents the results of a study performed to develop a comprehensive document that provides both state-of-the-art knowledge and state-of-practice design guidance to facilitate the use of EPS-block geofoam for slope stabilization and repair. This report includes the following five primary research products: (1) summary of relevant engineering properties, (2) a comprehensive design guideline, (3) a material and construction standard, (4) economic data, and (5) a detailed numerical design example.
The project was initiated to develop comprehensive design guidelines for use of geofoam in slope stability applications. According to the Digest, geofoam use is becoming more widespread in the U.S., but the adoption of it as a routine roadway construction material has been slowed by lack of design guidelines.
Although EPS-block geofoam for road construction is an established technology and despite the more than 30 years of extensive and continuing worldwide use of EPS-block geofoam, it has been underutilized in U.S. practice because a comprehensive design guideline for its use as lightweight fill in roadway embankments has been unavailable. There was, therefore, a need in the United States to develop formal and detailed design documents for use of EPS-block geofoam in roadway applications.
Note: Okay – I’ll admit – I also do a blog for the Geo-Institute Deep Foundations Committee. as such, there are often things that I feel should be posted at both – to get the widest possible audience! So, if you have already been over there, this post will look very familiar. It is much easier to reuse a post written by yourself. – Robert
As a continuing effort to implement the LRFD design methodology for deep foundations in Louisiana, this report will present the reliability-based analyses for the calibration of the resistance factor for LRFD design of axially loaded drilled shafts using Brown et al. method (2010 FHWA design method). Twenty-six drilled shaft tests collected from previous research (LTRC Final Report 449) and eight new drilled shaft tests were selected for statistical reliability analysis; the predictions of total, side, and tip resistance versus settlement behavior of drilled shafts were established from soil borings using both 1999 FHWA design method (O’Neill and Reese method) and 2010 FHWA design method (Brown et al. method). The measured drilled shaft axial nominal resistance was determined from either the Osterberg cell (O-cell) test or the conventional top-down static load test.
Nearly 1,000 project teams submitted their best work to ENR’s regional "Best Projects" competitions. For each of the nine regions, our editors assembled an independent panel of industry judges to home in on the winners in 19 categories. The winners of the regional contests moved on to the national competition. A different set of industry judges examined the projects to distinguish the "Best of the Best" in teamwork, success in overcoming challenges, innovation and quality. This year, a new award honors the safest project, judged by industry safety experts in both the regional and national competitions. Also, ENR’s editorial staff chose one special project as the "Editors’ Choice" to represent the pinnacle of design and construction excellence.
The Audubon Bridge won the Editor’s Choice – the editorial staff’s selection of the “pinnacle of design and construction excellence”. Congratulations to everyone at Audubon Bridge Constructors (Flatiron, Granite and Parsons), Louisiana DOTD, and all who worked on the project!
The world of social media or on-line networking sites continues to grow. Some of the sites offer opportunities for industry groups or committees to have groups that provide a place for discussion on specific topics relevant to the group or committee. DBA staff members are active on many technical committees in the Geo-Institute, DFI, PDCA, and ADSC. The G-I Deep Foundations Committee has Groups on both GeoWorld and LinkedIn open for anyone to join – not just committee members.
GeoWorld is the online professional networking site for geotechnical engineers and associated fields. It was launched last year and is growing. If you aren’t a member, click here to join. Once you join you will find all sorts of groups and other avenues for networking within the geoengineering community, including a group for the DFC (look for Technical Committees in the Groups area). Or just click the icon below to go to the group.
LinkedIn (as many of you already know!) is a social media site for all professions, providing networking opportunities for many purposes (industry news, technical advice, job seeking, keeping up with colleagues, etc.) . To find the DFC group, click on the icon below.
In addition to the G-I DFC, the DFI and the ADSC have groups on LinkedIn – go there by clicking on the logos below:
Check out these and other groups – join a discussion, or start your own!
An article coauthored by Dan and Dr. Paul Mayne, P.E. of Georgia Tech on geotechnical engineering in the Piedmont appeared in the November/December issue of the Geo-Institute’s Geo-Strata Magazine. The four page piece includes a brief overview of Piedmont geology, a discussion on sampling and testing of Piedmont soil and rock, a description of some of the unique engineering properties of Piedmont geomaterials, a discussion on the standard of practice for foundation design within the region, and a discussion on the value of engineering experience. Examples and data from research and construction projects Dan and Dr. Mayne have been involved in are scattered throughout. To read the article yourself, click here or pickup the latest copy of Geo-Strata.
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.