Get the New FHWA Drilled Shaft Manual
Get the NCHRP Synthesis 418 – Pile Criteria From Test Pile Data
Dan’s Speaking Schedule March 16, 2012 - "Advanced" Design and Construction Issues with Drilled Shaft Foundations; Case Histories - ADSC Equipment EXPO and Technical Conference - San Antonio, Texas
March 26-28, 2012 - State of the Art and Practice for Drilled Foundations - GeoCongress 2012 - ASCE/Geo-Institute - San Francisco, California
Other DBA Team Speaking Appearences Tim Siegel (January 22, 2012): Innovative Techniques for Characterizing Karst Terrain, Workshop on Geo-innovation in Subsurface Exploration, TRB Annual Meeting, Washington, D.C.
John Turner and Robert Thompson (February 21-23, 2012): NHI Drilled Shaft Course - Kansas DOT, Topeka, Kansas
Robert Thompson (February 24, 2012): Conservatism in Drilled Shaft Design When
Utilizing Rock Sockets, Alabama Transportation Conference, Montgomery, Alabama
Tim Siegel (March 15, 2012): Micropile Design Installation and Performance for the Foothills Parkway, ADSC Equipment EXPO and Technical Conference, San Antonio, Texas
Robert Thompson (March 15, 2012): Full-Scale Load Tests on Drilled Shafts in Tennessee and Georgia, ADSC Equipment EXPO and Technical Conference, San Antonio, Texas
Erik Loehr (March 15, 2012): Slope Stabilization Using Micropiles, ADSC Equipment EXPO and Technical Conference, San Antonio, Texas
TBA (April 10-12, 2012): NHI Drilled Shaft Course - South Carolina DOT, Columbia, South Carolina
Conferences, Meetings, Seminars, Workshops
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By David Graham, on November 9th, 2011

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.
By Robert Thompson, on July 31st, 2011

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.
By Robert Thompson, on February 1st, 2011
On December 29, 2010, Audubon Bridge Constructors recently “closed” the main span of the John James Audubon Bridge between New Roads and St. Francisville, Louisiana. Watch the video featured at the top of the page at the bridge link to hear about the bridge, including the drilled shaft foundations! For something really fascinating, go to the webcams here and scroll back through the various dates. They have archived images all the way back to start of construction.
Photo: Chris Usery, Figg Bridge Inspectors
The last cables were installed on January 3, 2011 as noted on the project website:
The last two cable stays of the longest cable-stayed bridge in the Western Hemisphere were installed on January 3, 2011, five days after the spans were connected. The John James Audubon Bridge, Louisiana’s newest crossing over the Mississippi River, now has all of its 136 cable stays in place.
This bridge will be the longest cable-stayed bridge in North America when it opens later in 2011. Again, from the project web site:
The spans of the longest cable-stayed bridge in the Western Hemisphere were connected on December 29, 2010, stretching 1/3 of a mile over the Mississippi River. The John James Audubon Bridge, connecting Pointe Coupee and West Feliciana parishes in Louisiana, is approximately 92% complete. Construction of the spans began from both sides of the 500-foot tall towers earlier this year. Both sides continue to progress at a rapid pace, and now the meeting of the spans has occurred.
Steve Dapp and I had the pleasure of working with many great people during our time on site (much more time for Steve than for me!) during foundation construction. One of them, Chris Ursery of Figg Bridge Inspectors, has been great about providing us with photos now and then to keep us updated of some of the details of the bridge construction. Chris has granted us permission to share a few of his recent photos, which are shown below or can be seen in our web albums here.
Previous post on Audubon Bridge.
By Robert Thompson, on January 3rd, 2011
The kcICON project in Kansas City has been completed six months ahead of schedule and within budget with all lanes and ramps being open on December 18th. Demolition has begun on the existing Paseo bridge. You can see some photos of the demolition (like the one in this post – thanks kcICON!) at their Facebook page. It was a great experience for us to have been a part of this project. If you want to see all of our previous posts on this, click here. Other points of interest are linked below.
The Kansas City District of MoDOT
ENR
DBA Project Page
kcICON Facebook Page
kcICON web page
By David Graham, on December 10th, 2010

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.

Axtell, P.J. (2010). “Mississippi River Bridge Project Includes Record Load Test: A Three Part Story”, Foundation Drilling, Vol. 31, No. 7 September/October 2010.
By Robert Thompson, on November 2nd, 2010
Paul received a few photos of the kcICON bridge that are just too cool not to share. These were sent to him by Massman Construction. These were taken in September of this year. MoDOT’s Flicker album of the dedication ceremony is here. The new bridge was dedicated and partially opened to traffic (southbound) on September 27th. The northbound traffic was shifted to the new structure on October 22nd. All of the bridges and ramps for the project will be opened by the end of the year – 6 months ahead of schedule. Can’t wait to see it after the exisitng bridge is demoloshed, though it is a pretty cool image with the old and new bridges together. Updates for the project are on the project Facebook Page.
Click here for previous posts on kcICON.



By Robert Thompson, on August 30th, 2010

The Lunda/Ames design-build joint venture (Lunda Construction Company of Black River Falls, Wisconsin and Ames Construction, Inc. of Burnsville, Minnesota) has been awarded a contract to build the new Highway 61 Hastings Bridge over the Mississippi River in Hastings, Minnesota. Parsons Transportation Group is the designer and DBA is performing geotechnical design of the bridge foundations and settlement mitigation as a sub-consultant to PTG.
Here is the existing bridge that is being replaced (viewing from upstream):

In addition to several relatively large approach spans, the new bridge will include a 545ft long free-standing arch main span with four lanes of traffic and a 12 foot wide common use pedestrian/bike path. The new bridge will allow additional parking and an artistic plaza area south of the river. An anti-icing system will be installed to help achieve the 100-year design life.
On the south side of the Mississippi River, the bridge foundations will consist of spread footings bearing on dolostone bedrock. The remaining bridge foundations will utilize 42in diameter pipe piles. Several Statnamic load tests, both axial and lateral, will be performed by our friends at AFT.
Settlement mitigation is required beneath the North Embankment due to several relatively thick and deep strata of compressible fine-grained soils. The embankment will also be heavily instrumented to evaluate performance of the embankment and mitigation technique.
Preliminary work including subsurface investigation has begun. The subsurface investigation is being performed by Braun Intertec under sub-contract to DBA. Test piles will be installed in early September, 2010 with subsequent load testing soon after.
The awarded design-build contract is for $120M. The estimated project completion date is May 13, 2013.
DBA Project Page here.

Mn/DOT Hastings Bridge Project Home Page
Here is a sampling of the local news on the project award:
Hastings Star-Gazette: Many articles, ongoing
9/22 Star Tribune: New Hastings Bridge is on the way
July 1 South Washington County Bulletin: Bridge design chosen: It will be the tied-arch
July 1 Minneapolis/St. Paul Business Journal: Lunda/Ames team wins $120M Hastings Bridge contract
By Robert Thompson, on May 25th, 2010
As geotechnical/foundation engineers, we don’t usually get to see much of what happens on a project after the foundations are completed, especially a project like a large bridge that can take years to complete. Technology such as the Internet, webcams, and digital photography have made it easy for us to see how things are progressing on projects, as well as maybe get images of the completed structure. As I have noted before, some projects are using Twitter and Facebook to keep the public informed on closures, delays or overall project progress as part of good public relations. Her are some updates on a few of our recent projects.
kcICON:
The main span is well underway, including the cables. The kcICON Facebook page is here.

Audubon Bridge:
Check out the webcam. You can download images if you like. YOu can also do a time-lapse from Day 1 of construction.
Beck Street Bridge:
Part of the I-15 Express Link project in Salt Lake City, UT. The photos below I obtained from the photos page on the project web site. We were involved in the design and construction of the foundations for the Beck Street Bridge only.
 
By Robert Thompson, on May 10th, 2010

With all of us visiting construction projects across the country, occasionally we take a photo that appears to be somewhat “artistic” – maybe the lighting (or lack of), or the aspect. I have assembled a few such photos submitted by DBA engineers in the first installment of the DBA Artistic Construction Photo Contest. Included in this installment are such items as: “Daybreak on Night Shift at JJA” and “Fountain” by S. Dapp, the series “Evolution” by P. Axtell, “GI Rig at Sunset” by T. Siegel, and “Piles in the Mist” by R. Thompson. This first volume has more photos of mine than others, but we’ll work on better balance in future volumes.
Feel free to “vote” for your favorite in the comments. I’ll try to update periodically as we have more “worthy” photos!
By Robert Thompson, on May 4th, 2010
The Spring 2010 issue of Deep Foundations from the Deep Foundations Institute includes an article by Dan and Paul (with a little help from yours truly!). The article is based on our paper presented by Dan at the 34th DFI Conference on Deep Foundations last October in Kansas City.
The kcICON project continues to roll along. Check out their Facebook page where they have lots of photos and links to their YouTube page. They recently completed the widest bridge deck pour ever for MoDOT.
Go to our Publications page to see the article, or click the image below.

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