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 Robert Thompson, on February 2nd, 2012
 The report for the ADSC Southeast Chapter Lawrenceville, Georgia Test Site is complete and published (link below).
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.
Thompson, W.R., Brown, D.A., and Hudson, A.B. (2012). “Load Testing of Drilled Shaft Foundations in Piedmont Rock, Lawrenceville, GA, Report for ADSC Southeast Chapter, January, 2012.
By Robert Thompson, on November 17th, 2011
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 receiving the 2011 DFI Distinguished Service Award
Robert receiving the Special Recognition Award for the Christopher S. Bond Bridge Project
Paul and Erik at the reception before the awards banquet
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 November 2nd, 2011
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.
By Robert Thompson, on October 2nd, 2011
 Greetings to all Terzaghi fans! Yes, it is that time of year again, where our thoughts turn to the anniversary of the birth of one of the greats in our field.
Last year I had a football themed post (college football, in case you were wondering…and that is American football for our fans outside the U.S.) since Terzaghi’s birthday was on a Saturday. Since I am not a big pro football fan, and since I used football last year, I figured I would do something different for this year’s weekend post.
The August 2011 edition of the International Society for Soil Mechanics and Geotechnical Engineering ISSMGE Bulletin is headlined with an article on the history of ISSMGE: “THE ISSMGE FROM 1936 TO 2011 A RETROSPECTIVE ON THE OCCASION OF THE 75TH PLATINUM JUBILEE ANNIVERSARY” by Kenji Ishihara and Michele Jamiolkowski. The Bulletin is in two parts at this link. The article is an outstanding work providing an excellent account of the start of ISSMGE as an international conference and its evolution into the ISSMGE we know today.
It should be no surprise that Prof. Terzaghi was very active and one of the key figures in the formation and success of ISSMGE, which began as the International Conference on Soil Mechanics and Foundation Engineering (ICSMFE). Many of the giants of soil mechanics and geotechnical engineering on which we base al of our work were instrumental in the start of ICSMFE and its impacts on our profession. As for that time in history (1936) and how it was important to our field:
The time had come to hold a Conference aimed at exchanging and sharing information on Earth and Foundation Engineering.
It was Professor Arthur Casagrande (assistant professor of Harvard University) who sensed the timing, conceived the idea and carried out the herculean task of running the conference all the way through, in his role of Secretary General, with K. Terzaghi (Professor of Technical University of Vienna and visiting Professor of Harvard University) as Chairman. Professor Peck once remarked “Our Society owes an enormous debt to Arthur Casagrande for his conviction that the time was right for the International Conference and to his tremendous efforts to organize it“.
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Since the first ICMSFE was so successful, it became clear that the Conference should not remain a one-off event but should, instead, be continued within a few years, possibly being held in Holland where earthwork engineering is so crucial to the country.
It was also requested to set up a permanent international organization. Thus it was decided to establish International Committees consisting of National Committees with K. Terzaghi as President and A. Casagrande as Secretary. It was also decided that at the next Conference the International Committees would submit the draft of the Constitution and of the By-laws, which are essential for the Society to become a permanent organization.
There was at that time a widespread awareness that it was the moment to set up a common denominator institution that would group engineers with diverse backgrounds but involved in our discipline.
 Portion of group photo from 1st ICSMFE, 1936. (From ISSMGE Bulletin Vol 5, No 4, August 2011, p3)
 Photo of Terzaghi addressing the opening session of the 4th ICSMFE, 1957. (From ISSMGE Bulletin Vol 5, No 4, August 2011, p7)
And the rest, as the saying goes, is history!
As an editorial note on the first year, Ishihara and Jamiolkowski offer this observation:
It is commonly recognized that K. Terzaghi is the originator of modern soil mechanics and foundation engineering and therefore father of our profession. After tracing the history of development, the writers had a strong belief that this is true. Not only was he always a leading figure in the forefront, but he conveyed strong messages on the role and importance of the soil mechanics and foundation engineering every time he participated in the ICSMFE. We are very much impressed by his enthusiastic and heartfelt message to our community.
No less important was the role played by Arthur Casagrande. He was instrumental in persuading the President of Harvard University to host the conference and carrying out all arrangements for organizing the first International Conference on Soil Mechanics and Foundation Engineering. The great success of this conference contributed greatly for establishing the place of soil mechanics in engineering practice throughout the world. He also dedicated himself to the ISSMFE as the 3rd President between the periods of 1961 in Montreal to 1965 in Paris.
There is a saying that for a great religion to be established, there always are two key-role playing giants. For Christianity Jesus Christ is the originator and his disciple Saint Paul was the great evangelist. For Greek philosophy, Socrates was the great philosopher and it was Plato who was the greatest disciple. Terzaghi and Casagrande are considered as a combination in the same context. Without Terzaghi, Casagrande would not have been so well-known. Had there not been Casagrande, the fame of Terzaghi would have developed in a different format.
Now neither I nor the authors are suggesting that soil mechanics is a religion, but their point on the timing and combination of Terzaghi’s and Casagrande’s work was critical to what we see as the field of soil mechanics/geotechnical engineering today. Without these two and others seeing a need, taking charge, and filling that need, we could very well be viewing things from a completely different framework.
So as we reflect on this celebrated day, let’s remember not only Prof. Terzaghi’s great technical achievements, but also his role as a leader (along with many others) shaping our field of practice and our professional societies.
By Robert Thompson, on September 26th, 2011
 It seems that social media and on-line communications have become a major part of our day-to-day communications. If you are like me (Robert), I find it rather annoying at times to filter through what you get to find what you really want or need. Now there is an on-line social networking/community for the geoengineering field – GeoWorld. This new “spot on the web” is a collaboration of Geoengineer.org and ISSMGE (International Society for Soil Mechanics and Geotechnical Engineering).
After more than two years of development, Geoengineer.org, in collaboration with the ISSMGE, is pleased to announce the development of Geoworld!
Geoworld is a new, free, professional networking platform for professionals, companies and professional organizations in the geoengineering profession. It promotes professional networking, collaborations and information dissemination at a global scale.
Geoworld revolutionizes the way information is circulated and even generated in the geoengineering field. It will serve as a platform to promote professional interactions, foster the formation of formal and informal groups, and support innovation in the geoengineering field at a global scale.
Geoworld is very easy to use and powerful, and has features that are specifically suited for geotechnical engineering professionals. Hundreds of geotechnical engineers as well as companies and organizations have already joined since the first announcement of Geoworld last week.
Here is a video link introducing Geoworld.
Look for DBA and ask to become a Contact. Also look for me and other DBA folks. See you there!
By Robert Thompson, on August 31st, 2011
Dan will be honored at the DFI 36th Annual Conference on Deep Foundations in Boston, October 19 to 21. He will receive the award at the annual awards banquet on Thursday, October 20th. From DFI:
The Deep Foundations Institute is pleased to announce Dan Brown, P.E., Ph.D., as the recipient of the DFI 2011 Distinguished Service Award. The award, in its 31st year, honors individuals chosen by their peers for exceptional contributions to DFI and to the industry.
Brown began his career with a B.S. from Georgia Tech, and later received his Ph.D. at the University of Texas, Austin, in only 28 months, while working. He then taught at Auburn University for 22 years before setting up his own consulting firm in Tennessee. The Winter 2011 issue of the DFI magazine included a profile of Brown that chronicled the universal admiration and regard for him within the industry. He was cited by others for his expertise, his intelligence and ability to teach others. Brown and his firm are sought out for advice everywhere.
Follow this link to see the full press release. We’ll post pictures after the ceremony.
By Robert Thompson, on August 25th, 2011
 Tim has authored a Technical Note in the most recent issue (June 2011) of the DFI Journal. The note is entitled “Simplified Settlement Model for a Shallow Foundation on Composite Ground with Rigid Piles”. From the Abstract:
A piled raft refers to a shallow foundation that is structurally connected to the piles, while composite ground refers to a soil-pile matrix where the piles are not structurally connected. The design objectives for both a piled raft and composite ground are (excluding special considerations such as expansive soil): (1) to provide a sufficient ultimate resistance and (2) to distribute the load into the soil-pile matrix so that the settlement experienced by the shallow foundation is within tolerable limits. A simplified model is proposed for a shallow foundation on composite ground where the foundation settlement is estimated as the sum of the downward movement of the piles plus the downward movement of the shallow foundation relative to the pile head. The proposed simplified
model is applied using conventional geotechnical analyses for two hypothetical examples of shallow foundations undergoing compression settlement.
This paper was originally published in DFI’s bi-annual journal, Volume 5, No. 1 in June 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. ”
You can also subscribe to the DFI Journal here.
By Robert Thompson, on May 9th, 2011
After some lengthy delays, the rock-socketed drilled shaft research sponsored by the Southeast Chapter of the ADSC is back on track. A second site has been selected at the site of Foundation Technologies, Inc. in Lawrenceville, Georgia. This site will investigate the resistance of some of the rocks of the Piedmont for drilled shaft design. The first test site was in Nashville, Tennessee. The report of the first test site and other information can be found at the test site page. General information about the complete project, including a list of participating/contributing companies and organizations, can be found at the project page.
Bruce Long (Long Foundation Drilling Company) is the lead for the ADSC on this project and has requested interested parties to provide comment on the test plan for the second site (see links below). The hope is to have load testing occur this July if every thing comes together properly. Bruce sent the following email with some refresher material on the Nashville test site and an update on the startup for the Lawrenceville site:
First, I would like for everyone to know that the load test program jointly planned between the Atlanta area ASCE Geotechnical community and the Southeast Chapter of the ADSC is alive and well despite some longer than planned delays. The final boring data has been in hand for some time and Dan Brown and his group have reviewed this information and submitted a preliminary load test program for review and comment. This program is very similar to the test program that was performed in Nashville a couple of years back. For informational purposes, the results of that test program has resulted in an increased awareness of the available load carrying capacity in the limestone formations in the area. Historically, shafts were designed almost exclusively utilizing end bearing with the normal range of values allowed ranging from 60-100 KSF. In recent months, we have seen projects now being designed with recommended values ranging from 100 up to 250 KSF with an increasing number of designs also relying on skin friction values up to 25 KSF in sound limestone sockets. The information gained from these load tests has given area engineers increased confidence in raising the bar for future drilled shaft designs. This will result in lower foundation costs for owners of public and private projects alike. For those involved in the design process, better information will result in improved design values and an improved competitive position for those willing to utilize this data.
Now we are prepared to move forward with the planned testing in the Atlanta area. I have attached the final geotechnical report for your review. There are several people and companies that have generously volunteered their time and expertise to make this happen, Todd Barber with Geo-Hydro Engineers, Inc. being the most notable of these. His persistence and assistance was invaluable. Others that contributed in a variety of ways include Mactec, Golder Associates, Georgia Tech and GeoTesting Express. Thanks to everyone for their efforts.
Also attached is the preliminary memo from Rob Thompson of Dan Brown and Associates. What he has outlined are suggestions based upon the boring information for two separate Osterberg Load cell tests. One would be on a shaft that was hand-cleaned, while the second shaft would be machine-cleaned only. This would allow a comparison to determine the effects (if any) that traditional hand-cleaning has on shaft behavior. This memo is being sent out with the intention that review and comments from the geotechnical community be considered and incorporated in the final program. Depending upon the extent of comments, a final meeting could be necessary to discuss any proposed revisions. If suggestions are minimal, such a meeting might not be required. In this case, we would proceed with shaft installation and testing as soon as possible.
Thanks for your patience–I think that the final results will be worth the time. It has been very rare that full scale load testing be done in hard rock areas (Piedmont or Limestone), but if the results of our Nashville area testing are any indication, I think the results will definitely show that the effort was worthwhile.
Please take time to review this information and e-mail or call me with any comments that you might have. As soon as all comments have been reviewed, we will let everyone know our plan to proceed. I would like to have comments submitted to me by May 27, 2011. If there are any questions regarding our plans, schedule, etc., please feel free to contact me at your convenience.
I have linked the proposed load test plan memo and the boring information below. Bruce would like comments from interested parties to be submitted by May 27, 2011. Please submit comments to him at blong@lfdc.com.
A blog page for this test site has been created and will be updated as the project progresses. We intend to have a prediction contest similar to the one we had for the Nashville site, so keep checking for information. Better yet, subscribe to our blog using one of the social media links at the top of the right sidebar of the blog.
Load Test Plan Memo from Dan Brown (20 May 2010)
Summary of Test Borings from GeoHydro Engineers (26 Jan 2010)
By Robert Thompson, on March 24th, 2011
Paul gave a presentation recently at the Iowa ASCE Geotechnical Conference where he discussed two project case histories for LRFD design of bridge foundations. The meeting was held March 3, 2011 in Ames, Iowa. In his presentation, Paul gave an overview of the LRFD design procedure as it applies to foundations, reminding them that LRFD is not difficult and that it provides a logical framework for incorporating reliability into foundation design. Paul talked about our experiences using LRFD for foundation design for two bridges over the Mississippi River: the Hastings Bridge in Hasting Minnesota and the new I-70 bridge in St. Louis, Missouri. Both bridges are currently under construction.
A PDF of his presentation can be found at the link through the image below, or on our Presentations page.
Previous Hastings posts
Previous I-70 posts
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The report for the ADSC Southeast Chapter Lawrenceville, Georgia Test Site is complete and published (link below). 
