Drilled Shafts, Foundation Design, Load Testing

ADSC Load Test Research – Lawrenceville, GA Site – SCHEDULE UPDATE

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 Share Registrars 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.

DBA News

Dr. John Turner, P.E. joins DBA!

We are pleased to announce that John P. Turner, Ph.D., P.E., has joined our firm as a Senior Principal. Turner is Professor Emeritus, University of Wyoming, where he spent the past 25 years teaching and conducting research in geotechnical engineering. He has undergraduate degrees in both Geology and Civil Engineering and earned his doctorate in Geotechnical Engineering from Cornell University. John will bring his considerable expertise in design and construction of deep foundations to our practice. He is a co-author of the 2010 FHWA manual “Drilled Shafts: Construction Procedures and LRFD Design Methods” and the author of NCHRP Synthesis 360, “Rock-Socketed Shafts for Highway Structure Foundations”, as well as over 100 technical publications on the topics of deep foundations, earth retention, and landslide stabilization. Early in his career John was an engineering geologist with Herbert and Associates and he maintained his involvement in consulting throughout his academic career. Recent projects include design of rock-socketed drilled shafts for bridges at Pitkins Curve in Big Sur and the Antlers Bridge on I-5 in northern California. John is a recipient of the President’s Award and the Distinguished Service Award from the ADSC: International Association of Foundation Drilling. He has maintained active membership in ASCE for over 30 years and is a past chairman of the Committee on Deep Foundations of the Geo-Institute of ASCE.

DBA News, Micropiles

Dr. Erik Loehr, P.E. Receives ADSC Award

Erik L ADSC distinguished service award_c

Dr. Erik Loehr, P.E. was honored by the ADSC with the ADSC Outstanding Service Award, presented at the President’s Luncheon at their 2011 annual meeting in New Orleans, Louisiana (Feb 1 –5, 2011).   The award recognized Erik’s research in the use of micropiles for slope stabilization and as foundations.  From the March/April 2011 edition of Foundation Drilling:

ADSC’s Outstanding Service Award was garnered by Dr. J. Erik Loehr, University of Missouri, in acknowledgment of his research and educational efforts that advance the technical aspects of the http://ourbestbrain.com/brain-food-and-why-they-are-smart-choices-for-mood-and-brain-function/ industries.

Dr. Loehr is currently on the faculty of the University of Missouri and is a consultant with DBA.

Drilled Shafts, Foundation Design, Load Testing

ADSC Rock-Socketed Drilled Shafts in the SE Research Project Site No.2 – Comments Welcomed

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)

DBA News

Robert Thompson awarded the Diplomate, Geotechnical Engineering (D.GE) certification!

We here at DBA would like to say Congratulations! to Robert Thompson for receiving the specialty certification Diplomate, Geotechnical Engineering (D.GE) from The Academy of Geo-Professionals (AGP).  Robert received the certification at the recent Geo-Institute’s Annual Conference, GeoFrontiers, in Dallas, Texas.  The excerpt below comes from the AGP web site.  Robert is on the bottom row, second-to-last on the right.

 

AGP’s 5th Ceremony in Dallas, TX

AGP’s latest ceremony was held in conjunction with Geo-Institute’s Annual Conference, GeoFrontiers, in Dallas, Texas on March 13th at 7:00 PM Central. The ceremony, which was the Academy’s fifth, was the first held 2011. About 25 Diplomates were in attendance at this event, bringing the total number of Diplomates to over 200!

Drilled Shafts, Driven Piles, Foundation Design, Ground Improvement, Miscellaneous

Hastings Update and Photo Album

Well, I, David, have survived my first (and hopefully last) winter in Minnesota.  I spent most of January and February observing the installation of the Pier 5 drilled shafts at the new Hastings bridge project in Hastings, Minnesota.  In addition to the drilled shafts, there has been a lot activity at Hastings since Aaron last blogged about this project in January.  A link to his post is here.  All of the ground improvement piles for the column-supported embankment have been installed and approximately 75% of the caps have been poured.  The 42-inch piles and pile caps for Piers 8, 9, and 10 are also complete.  Piles for the north embankment retaining wall have been installed and construction of the wall has begun.  Excavation for the rock bearing spread footings that will support the south land piers is in progress.  Work at Piers 6 and 7 and on the north shore are currently on hold as the Mississippi River is experiencing its annual spring flood. The water level is about 14 feet above normal elevation.

I have taken the pictures Paul and I have collected over the last few months and uploaded some of the more interesting ones to a Picasa web album.  The pictures are generally in chronological order and cover most of the construction process from November of 2010 right up to the end of March 2011.  A link to our our video of a Statnamic load test at Hastings that Aaron blogged about is here.

Foundation Design, Miscellaneous

LRFD Design Procedures Case Histories – Iowa ASCE Geotechnical Conference

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.

PJA_Iowa ASCE_3 MAR 2011

Previous Hastings posts

Previous I-70 posts

DBA News

DBA has a logo!

DBA Logo

After 5 years, Dan Brown and Associates finally has a logo!  We tried to keep it simple, yet still reflect what we do best – deep foundations.  That means piles, micropiles, CFA piles, as well as drilled shafts!  While not necessarily the most exciting thing an engineering firm can do, it is part of growing up as a company. Hopefully you will see it more often at conferences and in publications.

Drilled Piles, Load Testing

Technical Note on ACIP Pile Load Testing

A technical note by Tim that appeared in the December 2010 issue of the DFI Journal has been added to our publications page.  Tim’s note examines some issues related to axial load testing of augered cast-in-place (ACIP) piles, also know as augercast piles or CFA piles, that are not covered in ASTM D 1143/D 1143M-07 Standard Test Methods for Deep Foundations Under Static Axial Compression.  Specifically, load hold time, unload-reload cycles, and fluctuations in incremental load are discussed as they relate to load testing for determining axial capacity or axial load distribution of ACIP piles.  Details of instrumented ACIP pile load testing are also covered.

Siegel, T.C. (2010). “Load Testing and Interpretation of Instrumented Augered Cast-in-Place Piles”, DFI Journal Volume 4, No. 2, December 2010, Deep Foundations Institute, pp69-71.

DFI requests that the following be included with all DFI papers we post:

“This paper was originally published in DFI’s bi-annual journal, Volume 4, No. 2 in December 2010.  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. ”

Drilled Shafts, Load Testing

Audubon Bridge Closure–The Span is Complete!

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.

Specialists in Deep Foundation Design, Construction, and Testing and Slope Stability Problems