Get the New FHWA Drilled Shaft Manual
Get the NCHRP Synthesis 418 – Pile Criteria From Test Pile Data
Dan’s Speaking Schedule September 12-13, 2012: Concrete used in Drilled Shaft Construction - ADSC/DFI Drilled Shaft Seminar - Denver, Colorado
October 26, 2012: Factors Affecting the Selection and Use of Drilled Shafts for Transportation Infrastructure Projects - 26th Central Pennsylvania Geotechnical Conference - ASCE/DFI - Hershey, Pennsylvania
Other DBA Team Speaking Appearances John Turner (September 12-13, 2012): Analysis & Design of Drilled Shafts - ADSC/DFI Drilled Shaft Seminar - Denver, Colorado
John Turner (September 12-13, 2012): Techniques for Drilled Shaft Construction - ADSC/DFI Drilled Shaft Seminar - Denver, Colorado
Conferences, Meetings, Seminars, Workshops
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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 14th, 2011
The Transportation Research Board of the National Academies has published a National Cooperative Highway Research Program synthesis report by Dan and Robert: NCHRP Synthesis 418–Developing Production Pile Driving Criteria From Test Pile Data. This synthesis provides a survey of the current practices used by transportation agencies to develop pile driving criteria, with special attention on the use of test pile data. The report covers issues related to developing driving criteria, the current practices used by the responding agencies, recommended useful practices that were identified, along with descriptions of the practical approach several agencies use to integrate a range of technologies to develop pile driving criteria under typical conditions. The information collected indicates that practices used by transportation agencies to develop pile driving criteria for production pile installation can be described as highly variable in terms of the level and sophistication of the testing performed.
Included in the report are:
- Responses from a survey sent to all 50 state departments of transportation plus the District of Columbia and Puerto Rico (44 of the 52 agencies provided responses).
- Interviews performed by telephone or in-person of nine of the responding agencies selected based on the written survey responses.
- A comprehensive literature review on the range of practices included in test pile programs and their use in developing production pile driving criteria.
- Discussions of the survey results.
- Useful practices identified from the surveys.
- Identification of research needs for this topic.
To purchase the print version of this report or get a PDF, follow this link to TRB. Click the “View This PDF” to get the PDF.
Please note that if you order the printed version, Appendices B and C (copies of the completed survey forms and interview notes) are available via download only.
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 June 27th, 2011
The planned second load test in the ADSC research project for rock sockets in the Southeastern U.S. is moving closer to execution. Bruce Long of Long Foundation Drilling Company provides this update:
To Fellow Load Testers,
We want to thank everyone who submitted questions or comments regarding the preliminary load test program submitted to us by Dr. Dan Brown. Those comments, and more, will be considered while fine-tuning the program.
Because we have several companies donating their time and money, we have to be flexible with respect to the installation and testing dates. We have tentatively selected some dates, but these are subject to change depending upon the workloads of those volunteering their efforts. We hope to begin shaft installation during the last two weeks of July (weeks beginning the 18th or 25th). The actual load testing would probably take place the week of August 8th, with the actual test date being decided upon by sometime in early July (I hope to give everyone at least a 3-4 week notice).
The actual test date would include a field day visit by all interested parties to the test site at Foundation Technologies office in Lawrenceville, GA. Activities will include a load testing discussion led by Dr. Dan Brown, along with lunch. We would then move to the test site where Loadtest, Inc. will be conducting the Osterberg Load Test on our first shaft. A discussion of the testing process and procedures by Loadtest will precede the actual testing (We will be submitting information later regarding a load test contest where each of you will get to predict the outcome of the test with a special prize going to the winner). We also hope to be drilling on the second shaft that day and will be discussing the drill rigs, tools, and other equipment being used, as well as having the other Osterberg cell available for viewing. This site visit proved to be very well received when we did it in Nashville at the last load test. We hope for a big turnout that day.
I wanted to give everybody a brief update and will be in touch when additional information becomes available in the near future. Thank you for your interest, and if anyone has any questions regarding this plan, please feel free to call me at your convenience.
Bruce Long
President
Long Foundation Drilling Co.
Previous post is here.
The test site page is here.
The main page for the research project is 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
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 19th, 2011

(Image source: LakeExpo.com)
DBA is part of a team led by Parsons Transportation Group that was selected to design the replacement of the Hurricane Deck Bridge over The Lake of the Ozarks in Camden County Missouri. MoDOT has awarded the design contract to Parsons. DBA will be the lead geotechnical engineer with Terracon on the team providing drilling and laboratory services, as well as some foundation engineering support services. Parsons was chosen due to the innovative approach the team proposed that includes reusing the existing piers (from ENR.com):
MoDOT chose Parsons for proposing an innovative approach to construction that involves the use of temporary pier widening and shifting the existing superstructure over. This method will allow traffic to be maintained on the existing bridge while the new bridge is constructed, potentially resulting in significant cost savings.
A little history of the bridge can be found at Go2Lakeofthe Ozarks.com, including how it got its name:
Hurricane Deck Bridge of Ozarks crosses the main channel of the lake of approximately mile marker 35. It carries Missouri highway 5 between Versailles and Camdenton. It was built in 1936 –five years after the lake filled. It was named as Hurricane Deck because it was heard that a tornado struck that area which was locally "Hurricanes". It is a nautical term associated with river steamboats. The Hurricane Deck was the uppermost deck which provides and allows everyone to experience the pleasant breezy place and the passing scenery.
Other news links:
Lake News Online – 12/2/2010
Lake Expo.com – 12/2/2010
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
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