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 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 David Graham, on January 17th, 2011
Last spring, DBA designed a composite ground improvement system for a new hospital as part of the Owensboro, Kentucky, Medical Health System. Tim performed most of the ground improvement design for the design-build project with Berkel & Company Contractors, Inc. The design is a composite ground system with a layer of compacted gravel above lightly reinforced cast-in-placed displacement piles (known commercially as CGEs). Spread foundations placed on the compacted gravel distribute the structural load to the soil and CGEs. The construction of the composite ground system began and was completed in the summer of 2010. The project has a designated webcam that allows the public to view the entire construction process. The webcam can be viewed here. We have also uploaded some photos of construction and testing of the CGEs here.
By Robert Thompson, on November 1st, 2010
 Dan recently played the part of storyteller at the Southeastern Transportation Geotechnical Engineering Conference (STGEC) 2010 conference in Charleston, West Virginia when he gave the lunch presentation on the conference’s first day. He took the audience on a trip down the Mississippi River from a foundation engineer’s perspective, talking about several bridges that DBA has had the pleasure to work on, or is still working on, along the river the last few years. Dan began with the I-35W Bridge replacement in Minneapolis, Minnesota and ended at the Huey P. Long Bridge in New Orleans, Louisiana. Stops along the way included the Hastings Bridge (Hastings Minnesota), the new I-70 Bridge (St. Louis, Missouri), and the Audubon Bridge (New Roads/St. Francisville, Louisiana). Dan covered some of the technical issues/problems associated with each project and the solutions applied to complete the foundations (or complete the design). It was a very informative talk presented in a unique way that everyone at the luncheon seemed to enjoy. Dan’s presentation is now available on our Presentations Page.
Posts on Hastings Bridge here.
Posts on I-70 Bridge here.
Posts on Audubon Bridge here.
Posts on the Huey P. Long Bridge here.
 Immediately after lunch, Robert made a presentation that described some of the pile load tests performed on two of the storm protection projects in New Orleans that DBA was privileged to be involved with through Kiewit. By following Dan, it provided a little continuity to the story as Robert took the group below the Huey P. Long Bridge to the levees and canals downstream of New Orleans. Robert’s presentation can also be found on our Presentations Page.
Post on the pile load tests here.
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 August 18th, 2010
Check out the bottom of my post on June 30th World Record O-Cell Load Test for some updates and new links to recent news articles.
By Robert Thompson, on July 25th, 2010
 Robert made a presentation at the recent Alabama Section ASCE 2010 Summer Meeting on our participation in some pile load tests on a couple of the storm protection projects in New Orleans (see previous post here). DBA worked for Kiewit Engineering Company (KECo) and the two joint ventures on the projects, providing geotechnical consulting. We are collaborating with KECo on a couple of papers (maybe more) that include the test data. This presentation covered the basics of the test pile programs, highlighted some of the results, discussed the measured setup values for the piles (driven in the soft Louisiana clays), and looked at some comparisons of the dynamic and static load test results to the pile resistance predictions made by DBA during the course of our work. Please note that the Corps of Engineers (and their consultants) were the design engineers. Our work was in support of the contractor joint ventures, especially evaluating pile drivability and installation issues.
Some of the photos included in the presentation were obtained from the public Flickr albums posted by Team New Orleans, U.S. Army Corps of Engineers. There are a lot of good photos there of many of the ongoing projects around New Orleans, as well as an album of historical photos.
You can check out several webcams at the West Closure project here.
You can see Robert’s presentation here.
UPDATE (11/1/10): I have replaced this presentation with a similar one presented at the STGEC 2010 conference in October. The link now directs to the more recent presentation.
By Robert Thompson, on July 7th, 2010
 Although I have known for several weeks that the manual was finished (I work for one of the authors, after all!), I was waiting for the FHWA to post the link for the new manual before posting this…and now it is here! My friend, Randy Post, has an outside review (meaning not connected to one of the authors!) over at his blog Geoprac.net. Not only did he get “the scoop” on me, but he covers some of the highlights of the “what’s new” with the new, fully revised manual. The biggest change is completely re-writing the design sections to follow LRFD as well as to update the methods for calculating soil and rock resistance. As Randy also notes, the manual has been given a Geotechnical Engineering Circular (GEC) designation: GEC 10. Make sure and go read his review, as well as check out the other things on his blog (disclosure by Robert: I am an occasional contributor there).
The manual’s authors are three of the country’s top experts in drilled shaft design and construction: our own Dan A. Brown, Ph.D, P.E. , John P. Turner, Ph.D, P.E. of the University of Wyoming, and Raymond J. Castelli, P.E. of Parsons Brinckerhoff. As with any major FHWA publication such as this, there was significant industry involvement in the review process through various technical committees and individuals from ADSC, DFI, and Geo-Institute. A note from Dan:
The completion of this manual is a great relief and satisfaction. Many thanks to John Turner’s hard work and also for Ray Castelli’s diligent work to review and make us better. Special thanks to PB Project Manager Jeremy Hung and our FHWA sponsor Silas Nichols for their dedicated efforts to help get this done, and to all of you who contributed.
Dan and John have been using the material in the NHI course this fiscal year, having done some pilot courses the previous year. Some NHI courses, including the Drilled Shaft course, can be hosted by non-government groups. There are also some public seats available occasionally at DOT hosted courses. The NHI catalog page for this course is here.
Download Drilled Shafts:Construction Procedures and LRFD Design Methods, 2010.
Also linked on our Publications page.
Update (7/12/10): For those that prefer the feel of a printed volume in their hands, the ADSC: The International Association of Foundation Drilling will be the distributor of the printed volume of the manual through their Technical Library. It will be available soon, according to ADSC. We’ll post about it as soon as it is available.
Update 2 (8/19/10): The printed manual is now available.
By Robert Thompson, on June 30th, 2010
DBA was part of foundation engineering and construction history while participating in a drilled shaft load test for the New I-70 Mississippi River Bridge in St. Louis, Missouri. A new O-cell world record of 36,000 tons (bi-directional) was achieved on the test, besting the former record of just under 32,000 tons set in 2005 in Korea (see here).
The test shaft was built by MTA (a joint venture of Massman/Traylor Brothers/Alberici Constructors) as part of an Alternative Technical Concept (ATC) that MTA submitted in their winning bid. During the bid phase, the owner allowed ATC’s to be submitted by pre-qualified teams. These ATC’s were unique to the team that submitted them (e.g., each team was allowed to submit their own ATC’s if they desired, but the ATC’s were not shared amongst all the teams). DBA worked with MTA to develop an ATC that optimized the drilled shaft foundations shown in the “baseline” drawings provided by the owner. That ATC provided a more economical foundation solution that was accepted, bid, and awarded (note MTA also had the option of bidding the “baseline” drawings as-is). A full-scale load test on a dedicated test shaft using the Osterberg Cell (O-cell) test method was included in the ATC to: 1) prove the design values used for the resistance in the rock socket; and (2) take advantage of higher resistance factors for using a load tests as opposed to only calculations. The baseline drawings did not include a load test.
Loadtest, Inc. performed the load test. The bottom-up static load test applied slightly greater than 36,000 tons (bi-directional) to the shaft resulting in about 1/8in of upward movement of the shaft and about the same magnitude of downward displacement at the base. The rock socket was about 23ft deep and 11ft in diameter in very hard limestone. Four 34in O-cells placed at the base of the shaft were loaded to 150% of their rated capacity to achieve the record load.
UPDATE (8/4/10): The bridge was featured in the July 2010 issue of Civil Engineering magazine from ASCE in the “News” section. Follow the link below and then go to Page 30.
Civil Engineering July 2010
UPDATE (8/17/10): Press Release from MTA (contractor joint venture).
UPDATE (8/18/10): ENR.com Article
 
By Robert Thompson, on January 26th, 2010
I have added a recent paper that Dan and Steve contributed to concerning loess that is in the November, 2009 issue of the DFI Journal. The paper describes the results of site investigation and laboratory tests at a site in Kansas with loess deposits. The effectiveness of various correlations between field and laboratory tests and design properties are evaluated. Steve is currently working on the follow-up paper that evaluates lateral load tests of drilled shafts at the site.
Parson, R.L., Johnson, R.M., Brown, D.A., Dapp, S.D., and Brennan, J.J., 2009. “Characterization of Loess for Deep Foundations”, DFI Journal Volume 3, No. 2, November 2009, Deep Foundations Institute, pp14-24.
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