Category Archives: Bridge Foundations

DBA at DFI 36th Annual Meeting–Photos and Links

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).

PowerPoint Presentation – Alternate Technical Concept: Foundations for the New Mississippi River Bridge, St. Louis – Dan Brown, Ph.D., P.E – DFI 36th Annual Conference, Boston, MA, October 20, 2011.

Dan receives DFI 2011 Distinguished Service Award

Dan receiving the 2011 DFI Distinguished Service Award

Bond Bridge Special Recognition Award - DFI 2011

Robert receiving the Special Recognition Award for the Christopher S. Bond Bridge Project

Paul and Erik at DFI 2011 Awards Banquet Reception

Paul and Erik at the reception before the awards banquet

Hastings Bridge Receives Press as Foundations Near Completion

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.

Previous blog posts by Aaron and David can be found here:Hastings Bridge Update and Hastings Update and Photo Album.  Additional information can be found on the DBA project page here.

Audubon Bridge Foundations in Fall 2011 “Deep Foundations”

DFI Fall 2011_Audubon

Dan and Steve co-authored an article in the Fall 2011 issue of Deep Foundations (from DFI) that covered the foundations for the recently completed record-setting Audubon Bridge in Louisiana.  Dan and Steve cover not only the shaft testing, design, and construction, but also the unique cofferdam used for the tower foundations.  I recently highlighted an article by Sereno Brown, P.E. of Flatiron that covered the design and installation of the cofferdam in detail. 

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.

Dr. Steve Dapp…in Taiwan!

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 meeting is noted here on the TGS site.

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(Source: ISSMGE Bulletin Volume 5, No. 4, p82)

Audubon Bridge–Cofferdam Construction Article

LA-Civil-Eng-JJABridge

As noted earlier on this blog, the Audubon Bridge opened a little bit earlier than planned.  Although over a year old, an article recently came to my attention that puts a spotlight on the unique engineering and construction that went into the cofferdams for the two main bridge piers in the Mississippi River.  The article is “John James Audubon Bridge Project – Cofferdam Construction for the Main Span Pier Foundations”, published in the February 2010 issue of Louisiana Civil Engineer, the Journal of the Louisiana Section of the American Society of Civil Engineers.

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.

Download the article here.