Massive prestressed concrete girders, some of them setting a record for the longest concrete girders used on a Minnesota bridge, have been set at the New Hastings Bridge, currently under construction in Hastings, Minnesota. The largest girders are 174 feet long, 8 feet tall, and weigh 108 tons! There is a video of one of these huge beams being delivered on a 16 axle truck, below. An article from the December 2011 issue of Concrete Products magazine about the girders can be found here. To date, all of the girders between the north abutment and main span have been placed. Crews are preparing piers 5 and 6 for the main span steel arches, which are scheduled to be floated in by barge and lifted into place late this year. MnDOT has two web cams where the bridge construction and the arch construction can be viewed. The Minneapolis Star Tribune has also been following the construction. Their latest article, which hails the bridge as “a monumental marvel,” can be found here.
In addition to the ADSC EXPO 2012 earlier in March (see post here), the annual Geo-Institute meeting for 2012, GeoCongress 2012 , was held later in the month in Oakland, California. The conference featured a very large technical program with a variety of tracks covering geotechnical engineering topics. There were also the annual named lectures (Terzaghi, Peck, etc.) and other special events. Randy Post wrote about his time at the GeoCongress at his blog, GeoPrac.net. Check out all of his posts on the conference, including photos and video.
A key feature of this congress was the State of the Art (SOA) and State of the Practice (SOP) Lectures given throughout the four days. Thirty prominent engineers were invited to give the SOA/SOP lectures. Dan gave one of the SOP lectures with his highlighting advances in drilled foundation use and selection. His paper, along with all of the other SOA/SOP lectures, is included in GSP No. 226, Geotechnical Engineering State of the Art and Practice, Keynote Lectures from GeoCongress 2012. His presentation is linked on the image below.
During the regular technical sessions, John Turner presented a paper on a recent project case history on rock-socketed drilled shaft foundations used for a bridge . His paper is in the conference proceedings volume (GSP No. 225):
There were several of us presenting at the ADSC EXPO 2012 in mid-March: Dan, Erik, Robert and Tim. The EXPO is always a great event (occurs every 3 years) where equipment manufacturers and dealers bring out all of the big equipment (as Dr. Dave Elton at Auburn has been known to say: “It’s a classic case of big boys and big toys!”). It is a lot of fun to be able to walk through a large show of equipment and tooling that is all clean and painted – you can see what it is all supposed to look like! As an engineer, you can learn a lot about the latest tools, equipment capabilities, and the like from the sales and manufacturing reps. The ADSC always does a great job putting this event on, and this year’s venue a the J.W. Marriott Hill Country Resort outside San Antonio was fantastic.
Dan and Robert both had papers included in the proceedings. Links to the papers are below. Erik and Tim had presentations along with those that Dan and Robert gave on their papers. Links to the presentations are on our Presentations page.
The John James Audubon Bridge between New Roads and St. Francisville, Louisiana was officially completed February 27, 2012. The bridge was opened to traffic in May of last year, but was declared officially completed last month. This bridge has a special spot in the heart of DBA as it was one of the early large bridges we worked on as a company. Steve and Dan poured their energy and expertise into the project starting in spring of 2006, all the way to completion of the last foundations in 2010. Steve spent a good part of his life on site during foundation construction. I spent a fair amount of time there myself helping Steve cover things now and then, including observing the soil borings for the main tower piers during the design.
The JJA (as we like to call it) was the subject of one of my early posts when we started this blog in early 2006. You can scroll through the many posts made during our work on the project here, starting with the soil boring program.
Construction on the John James Audubon Bridge has officially come to a close. The new Mississippi River crossing is the longest cable-stayed bridge in the Western Hemisphere, with a 1,583’ main span. Located in south-central Louisiana, the Audubon Bridge connects West Feliciana Parish with Pointe Coupee Parish and is the only bridge between Baton Rouge and Natchez, Mississippi. Construction on the $409 million project began in 2006 and continued when the bridge was opened in May 2011 due to high water levels closing the St. Francisville Ferry sooner than expected.
"Although the Audubon Bridge has been open to traffic for nine months, it’s with a great sense of accomplishment that we are announcing the end of construction on this beautiful structure," said Department of Transportation and Development Secretary Sherri H. LeBas, P.E. "The completion of this bridge opens economic development in south-central Louisiana and will be a source of regional, statewide, and national pride."
I was finally able to make my first visit to the Bond Bridge in Kansas City since it was completed. It is a very beautiful bridge that fits well into the approach to Kansas City from the north. As foundation engineers, we don’t always get a convenient opportunity visit the large bridge structures we work on since our work is usually completed very early in the overall schedule. We are often too involved in other projects by the time a bridge is finished on which we were the foundation/geotechnical engineer. So, it was a personal pleasure to make a visit and drive over the bridge when John Turner and I flew into Kansas City on our way to Topeka to present the NHI Drilled Shaft Course earlier this month. Although it was a cloudy and cold day, I think the few photos I took with my phone (camera battery was dead!) turned out good. Mouse over each for a caption. Enjoy!
DFI held its 36th Annual Meeting October 18-21 in Boston, including the annual awards banquet. Dan was honored with the 2011 Distinguished Service Award at the banquet. The Christopher S. Bond Bridge in Kansas City, MO was honored with a Special Recognition award (one of 5 runners-up for the Outstanding Project Award). Photos of DBA folks at the event are posted below. All of the photos from the meeting can be found at this link.
Dan gave a presentation on the Alternate Technical Concept (ATC) that DBA supported for the I-70 Bridge over the Mississippi River in St. Louis, MO. The link to the presentation is below. (Some previous posts here and here and here; posts with links to other presentations here).
As massive concrete piers rise from the Mississippi river in southeast Minnesota, people have begun to take notice of what will become the longest free-standing tied-arch bridge in North America. A unique project in several respects, the new Hasting bridge has recently been featured in articles on the websites of ENR and Roads & Bridges. The ENR article is a republication of an article that originally appeared in the Minneapolis Star Tribune highlighting the construction process of the last year, with particular focus on the process of constructing the river piers. The Roads & Bridges article is a more technically in-depth piece written by the lead bridge engineer Vincent T. Gastoni, P.E., of Parsons Transportation Group. Both articles discuss some of the many geotechnical changes faced on this project. This excerpt from Roads & Bridges is a concise description of the pier foundations and some of the reasoning behind their selection:
The main river piers are concrete delta-style frames with the tied-arch superstructure fully framed into the pier through the knuckle connection. The stiffness of the foundation system was then integral to the overall force effects in the structure. The north pier is located in 190 ft of soft soils overlaying rock and supported on unfilled 42-in. driven steel pipe piles. Drilled shafts were investigated early but were not cost-effective, impacted the schedule and presented a risk to the existing bridge due to potential caving effects. Statnamic pile load testing was used to validate the vertical capacity and lateral performance of the 42-in. piles. The south pier footing is close to the rock surface; however, the rock was deeper, more sloped than expected, and the originally planned spread footing was changed to short drilled shafts during the final design. Dan Brown & Associates provided the team with geotechnical analysis and recommendations.
Our Tim Siegel pointed out that the statement “It’s a marvel of engineering that requires ingenious construction techniques, most of which are invisible to the drivers whizzing by overhead,” from the Star Tribune, is an accurate description of how our work as foundation designers and constructors is often viewed. Although much of the ingenuity and innovation that goes into the geotechnical aspects of projects often goes unnoticed by the general public, it is certainly refreshing to see articles like these. For us at DBA, it is even more refreshing to see our efforts credited by name as they were in the article by Vince when he wrote, “Dan Brown & Associates provided the team with geotechnical analysis and recommendations.”
For a design-build project with so many different geotechnical components (driven piles, drilled shafts, spread footings, retaining walls, a column-supported embankment, and light weight fill), it is hard to believe that our role as the lead geotechnical engineer is nearing completion just a little over a year after construction began. At this point, the only foundations that have yet to be constructed are some of the rock bearing spread footings at the south approach. DBA will also monitor instrumentation installed in the column-supported embankment for the next two years.
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During a recent trip to Taiwan, Steve had the opportunity to participate in a lecture on base grouted drilled shaft foundations. He was invited to speak at a meeting of the Chinese Taipei Geotechnical Society (CTGS), also known as the Taiwan Geotechnical Society (TGS), by Dr. Prof. San-Shyan, Lin, National Taiwan Ocean University (current president of TGS). The meeting was held at the National Taiwan University of Science and Technology.
His visit on 21 June 2011 was noted in the August 2011 issue (Volume 5, No. 4, p82) of the ISSMGE Bulletin. During his lecture, Steve talked about the experiences of DBA with base grouting drilled shafts at the Audubon Bridge and the Huey P. Long Bridge on the Mississippi River in Louisiana. Steve said that base grouting has become a very common technology in Taiwan for high rise structures supported on drilled shafts.
The article’s lead author, Sereno Brown, P.E., was the construction team’s Project Engineer for the design-build project. In the article, Mr. Brown outlines the issues that led to the team selecting a pre-cast concrete cofferdam over other methods, the design methodology, and then the construction of the cofferdam. The effort posed several significant design and construction challenges, including the sequence of lowering the cofferdam into place through a set of hydraulic jacks. The entire process was truly an amazing engineering and construction feat.
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