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."
Another paper featured in the December 2011 issue of the DFI Journal was authored by Steve and Dan, along with Dr. Bob Parsons at the University of Kansas.
The paper describes a program of lateral load tests on six drilled shafts installed in a loess deposit at a site in Wyandotte County, Kansas. The lateral load test data, along with site characterization data that included CPT data, were used to develop a hyperbolic model to generate p-y curves for use in lateral load analyses in cemented soils. The model should be applicable to many “c-phi” soils (soils with both a cohesion intercept and a friction angle, such as cemented soils). Degradation of the static soil model to account for cyclic loading effects is included in the new model.
This paper was originally published in the DFI Journal,Vol. 5 No. 2, December 2011, the bi-annual Journal of the Deep Foundations Institute. DFI is an international technical association of firms and individuals involved in the deep foundations and related industry. The DFI Journal is provided to DFI members at no cost electronically or can be purchased in print at www.dfi.org.
This paper is one of several papers and articles published form a series of research projects by KU and the Kansas DOT. Some of the previous work can be found at these links:
The new I-70 Mississippi River Bridge in St. Louis, Missouri is moving along and getting noticed in the news. Here are a couple of (somewhat) recent articles:
You can get real-time updates of the construction from three web-cams at this link. As I type today, the site is covered in snow. Very beautiful, unless you are trying to build a bridge on time!
The project page also has photo galleries and other neat stuff.
This is the second report from their research project on rock-socketed drilled shafts in the Southeast U.S. This report is from the Lawrenceville, Georgia test site where shafts constructed in metamorphic rock of the Piedmont geologic province were load tested using the O-Cell load test device. The report link is below. Additional information about the test site can be found at the Lawrenceville Site Page.
The first site of this project was in Nashville, Tennessee where shafts constructed in limestone were tested. Information on the Nashville Site and the test reports can be found at the Nashville Site Page.
Both reports will be the feature of a paper and presentation by Robert at the 2012 ADSC Expo, March 13-17, in San Antonio, TX. More information about the Expo can be found here.
The drilled shaft foundations for the new I-70 Mississippi River Bridge in St. Louis, MO are the subject of two recent papers written by Paul and Dan and published by DFI. Dan presented the paper focusing on the Alternate Technical Concept (ATC) process at the DFI 36th Annual Conference in October. (previous post here). A case history paper by Paul and Dan was published last month in Volume 5, Number 2 of the DFI Journal. Links to the papers are below, as well as on our Publications page. Other posts on this bridge are here.
This paper was originally published in the Proceedings of the 36th Annual Conference on Deep Foundations, the 2011 annual meeting of DFI. Go to www.dfi.org to purchase the procedings or for further information.
This paper was originally published in DFI’s bi-annual journal, Volume 5, No. 2 in December 2011. DFI is an international technical association of firms and individuals involved in the deep foundations and related industry. The DFI Journal is a member publication. To join DFI and receive the journal, go to www.dfi.org for further information.
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.
You can receive Deep Foundations every quarter (soon bi-monthly!), as well as the DFI Journal, by joining DFI. Get information on joining at this link – click on “Membership” at the top banner.
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