Tag Archives: Geotechnical Engineering Research

NEW PUBLICATIONS ADDED AND UPDATES TO THE WEBSITE

It’s been a while since we have updated everyone on some of the various publications we have added to our website, so I wanted to provide a few links to some of the newer additions to our Publications tab.  One magazine that members of DBA contribute to fairly regularly is Geostrata Magazine.  The Geostrata Magazine is a bi-monthly publication of the Geo-Institute.  You can join the Geo-Institute and gain access to the magazine by following this link:  https://www.geoinstitute.org/publications/geostrata.  Dr. Dan Brown published an article in the May-June 2020 edition about lessons learned from failures during pile installation with regards to driving stresses.  In the January-February 2021 edition, Dr. Erik Loehr contributed an article about recognizing the inherent value in site characterization.  Links for the articles are below.

Brown, D., E. (2020). “Learning from Pile Driving Failures,” Geostrata, May-June 2020.

Loehr, J. E. (2021). “Recognizing Value in Site Characterization – How Cool Would That Be?”, Geostrata, January-February 2021.

Speaking of the Geo Institute, Dan Ding and Erik Loehr recently co-authored a paper in the Journal of Geotechnical and Geoenvironmental Engineering (see link below).

Ding, D., Loehr, J. E. (2019). “Variability and Bias in Undrained Shear Strength from Different Sampling and Testing Methods,”Journal of Geotechnical and Geoenvironmental Engineering Volume 145, Issue 10, October 2019.

An organization that we actively publish papers with is the Deep Foundations Institute (DFI).  We have added papers from the last three years for the DFI Annual Conference as well as the The Journal of the Deep Foundations Institute.  Links to the papers are below.  To join DFI or learn more , click the DFI logo located in the left sidebar.

T.C. Siegel, T. J. Day, B. Turner & P. Faust (2019) “Measured end resistance of CFA and drilled displacement piles in San Francisco Area alluvial clay”,DFI Journal – The Journal of the Deep Foundations Institute, 12:3, pp 186-189.

Graham, D.S. and Axtell, P.J. (2019). “Case History: Comparison of CSL Results to Physical Observations,” Proceedings: Deep Foundations Institute 44th Annual Conference, Chicago, IL, USA, pp 420-427.

Axtell, P.J., Graham, D.S., and Jackson, J. (2018). “Drilled Shaft Difficulties and a Micropile Solution,” Proceedings: Deep Foundations Institute 43rd Annual Conference, Anaheim, CA, USA, pp 93-103.

Graham, D.S., Axtell, P.J., and Iverson, N. W. (2017). “Case History: Large Diameter Micropiles for the Highway 53 Relocation Project,” Proceedings: Deep Foundations Institute 42nd Annual Conference, New Orleans, LA, USA.

Dr. Dan Brown has also recently submitted an article to Pile Driver Magazine, which is a bi-monthly publication of the Pile Driving Contractors Association (PDCA).  To learn more about the PDCA or become a member, click on logo on the left sidebar. The magazine is free to access and can be found by clicking here while the link for Dr. Brown’s article can be found below.

Brown, D. (2020). “A comparison of factors affecting the static axial resistance of drilled and driven piles”, Pile Driver Issue 4 2020, Volume 17 No. 4, pp 60-78.

We have also added a few older papers that David Graham and Paul Axtell have published.  One, a case history for a micropile project, was for the International Society of Micropiles.  The other was for the 34th annual International Bridge Conference.  The links for  the papers are found below.

Axtell, P.J., Graham, D.S., and Bailey, J. D. (2017). “Statnamic Load Testing on a 406mm (16 in) Diameter Micropile,” International Society of Micropiles, Chicago, IL, USA.

Graham, D.S., Hasbrouck, G.T., Axtell, P.J., and Turner, J.P. (2017). “Reducing Longitudinal Demands on Tall Bridge Piers with an Anchored Abutment”, Proceedings of the 34th International Bridge Conference, 2017, National Harbor, MD, USA, pp 668-672.

Finally, we have also updated our About Us tab to reflect the change in leadership announced back in April of 2020 and provide an updated view of our current staff here at DBA.  The names of each individual are links to their respective resume. 

DBA Grows – 2020 Edition!

DBA is happy to announce our two latest additions to the team: Dan Ding, Ph.D., P.E. and Andy Boekmann, Ph.D., P.E.  Dan joined us as a Project Engineer in October of 2019 while Andy came on board as a Senior Engineer in February of this year.   Read a little bit about both of them below.  Go to our About us page to see their resume as well as everyone else on the DBA Team.

Dan Ding, Ph.D., P.E.

Dan received her Ph.D. degree in Civil Engineering from the University of Missouri. Dan specializes in site characterization, geotechnical laboratory testing, Load and Resistance Factor Design, and reliability analysis. Before joining DBA, Dan worked as an adjunct assistant professor at the University of Missouri to teach undergraduate and graduate engineering courses as well as conduct national and state research projects. She also worked as a laboratory geotechnical engineer at Geocomp in Acton, MA for a year after graduation.  Dan is based in Columbia, Missouri.

Andy Boeckmann, Ph.D., P.E.

Prior to joining DBA, Andy was a research engineer at the University of Missouri, where he performed research on topics including post-grouted drilled shafts, reliability of geotechnical designs, foundation reuse, and geotechnical asset management. Andy also earned a Ph.D. at the University of Missouri; his dissertation examined the reliability of foundation designs based on site-specific load tests. Andy is the lead author of two NCHRP Synthesis reports, including Current Practices and Guidelines for the Reuse of Bridge Foundations. Prior to working at MU, Andy was a consulting geotechnical engineer for URS Corp. in St. Louis, where he performed design and analysis for large projects, including post-Hurricane Katrina levee design in New Orleans. Andy is an active member of the Deep Foundations Institute, including serving as the vice-chair of the Subsurface Characterization Committee.  He is also based in Columbia, Missouri.

NCHRP Report 697 – Design Guidelines for Increasing Lateral Resistance of Bridge Pile Foundations

nchrp_rpt_697_coverWe have added a link to the NCHRP Report No. 697 Design Guidelines for Increasing Lateral Resistance of Bridge Pile Foundations.  This report was published in 2011 and authored by Kyle Rollins, Pd.D., P.E. of Brigham Young University and our own Dan Brown.  Dr. Rollins is a Professor in Geotechnical Engineering specializing in earthquake engineering and soil improvement.

 

In the forward of the report, Andrew Lemer of TRB writes:

NCHRP Report 697: Design Guidelines for Increasing the Lateral Resistance of Highway- Bridge Pile Foundations by Improving Weak Soils presents design guidance for strengthening of soils to resist lateral forces on bridge pile foundations. Lateral loads may be produced by wave action, wind, seismic events, ship impact, or traffic. Strengthening of soil surrounding the upper portions of piles and pile groups—for example by compaction, replacement of native soil with granular material, or mixing of cement with soil—may be more cost-effective than driving additional piles and extending pile caps as ways to increase the bridge foundation’s capacity to resist lateral forces associated with these loads. This report presents computational methods for assessing soil-strengthening options using finite-element analysis of single piles and pile groups and a simplified approach employing commercially available software. The Additional resources and design guidelines will be helpful to designers responsible for bridge foundations likely to be exposed to significant lateral loads.

Be sure to browse all of the nifty reports and projects in geotechnical and foundation engineering at TRB here.

Also check out our Publications page regularly for new postings.

FHWA Research Project: Post-Grouted Drilled Shafts

DSCN1233

(Note from Robert: I used material from the team proposal and the article referenced below for this post, with the authors’ permission. Also, DBA is a significant participant in the project and we hope to provide updates as things move along.)

The Federal Highway Administration (FHWA) has partnered with the ADSC: The International Association of Foundation Drilling (ADSC-IAFD) on a comprehensive research project on post-grouted (also called base grouted or tip grouted) drilled shafts. The FHWA and the deep foundations industry are very interested in the proper application and implementation of post-grouting for drilled shafts. The potential benefits of post-grouting have been demonstrated, and the industry has attempted to capitalize on these benefits in numerous ways. Some of these attempts have been successful while others have not, which has led to confusion and even misapplication of post-grouting technology within the industry.

The project will include an extensive synthesis of existing practice and literature, evaluation of theoretical concepts, full-scale field testing, and comprehensive analysis of the field testing to develop design methods. Each phase of work will have a set of deliverables that will go through a rigorous review process. The project is anticipated to be completed sometime in 2014.

The four main objectives of the research program are:

  1. Bound the application of the post-grouting technology for the current state-of-knowledge;
  2. Quantify the improvement mechanism(s) for the post-grouting of drilled shafts;
  3. Develop design methodology(ies) for appropriate applications of post-grouting; and,
  4. Provide method(s) for verification.

To accomplish these objectives, a highly qualified and experienced team of practitioners and researchers has been assembled to execute this project. This team includes industry representatives from construction, design, and academia that can bring a variety of perspectives to the project as well as respond to input from the many stakeholders within the geotechnical and transportation design and construction communities that routinely implement this technology.

Dr. Antonio Marinucci, MBA, P.E., of ADSC-IAFD will serve as Project Manager for the project and will be responsible for coordination and oversight of all project activities. Dr. J. Erik Loehr, PE, of the University of Missouri will serve as Principal Investigator (PI) with overall technical responsibility for the project including technical planning, data collection, synthesis, interpretation, and document production. Three Co-Principal Investigators (Co-PIs) will collaborate with Dr. Loehr to address the technical aspects of the project: Dr. Marinucci of ADSC-IAFD; Dr. Dan Brown, P.E., D.GE of Dan Brown and Associates, PC; and Dr. Jesús Gómez, P.E., D.GE of Schnabel Engineering Consultants, Inc.

An Advisory Panel will be utilized to provide additional objective technical insight regarding planning and execution of the project and development of the project deliverables, as well as unique expertise regarding specific aspects of the proposed work. The Advisory Panel will include:

Mr. Tom Armour, P.E., D.GE of DBM Contractors, Inc.

Dr. Donald Bruce, CEng, D.GE of Geosystems, LP

Mr. Allen Cadden, P.E., D.GE of Schnabel Engineering Consultants, Inc.

Dr. Steven Dapp, P.E. of Dan Brown and Associates, PC

Mr. Michael Muchard of Applied Foundation Testing

Dr. Miguel Pando, PEng of the University of North Carolina at Charlotte.

To provide objective review and evaluation of project plans and deliverables at key stages of the project, a formal Peer Review Panel will be formed composed of representatives from throughout the drilled shaft industry. The peer review process will be coordinated through the drilled shaft technical committees of each of the major stakeholder organizations in the U.S.: the ADSC-IAFD Drilled Shaft Committee; the ASCE/Geo-Institute (ASCE/GI) Deep Foundations Committee; the Deep Foundations Institute (DFI) Drilled Shaft Committee; and the Transportation Research Board (TRB) Committee on Foundations of Bridges and Other Structures.

The final component of the project team will be the ADSC-IAFD Contractor Members, Associate Members, and Technical Affiliates that will provide substantial in-kind contributions to meet the needs of the proposed experimental programs. Likely in-kind contributions from ADSC members will include provision of testing sites and facilities, construction equipment, materials, testing apparatus, as well as services necessary to complete the proposed project.

The configuration of this team consisting of the PIs, the Advisory Panel and the Peer Review Panel will provide a thorough review process as well as “checks-and-balances” against any perceived or realized personal biases regarding the use of post-grouting with drilled shafts. It is believed that the recommendations resulting from this effort will reflect a consensus on the application, design and construction of base-grouted drilled shafts that will be accepted by the industry at-large. This should result in consistent application of this technique by the industry.

For a detailed description of the project, see the article linked below from May 2012 issue of Foundation Drilling magazine, available from the ADSC-IAFD. In the article, Dr. Marinucci provides the first in a series of updates that will be published reporting the progress of the research through the various phases of the project. We’ll provide posts here as new reports are released, as well as posts of all the action when field work gets started!

ADSC-FHWA Research Project: Evaluation and Guidance Development for Post-Grouted Drilled Shafts for Highways

Early Statnamic Lateral Load Test Paper by Dan

While at the 2012 Geo-Congress I purchased a couple of books at the ASCE bookstore.  One was GSP 88: Analysis, Design, Construction and Testing of Deep Foundations, Proceedings of the OTRC ‘99 Conference. There are several interesting papers in the GSP, including an early paper by Dan on lateral Statnamic testing.  A full scale lateral load test was performed on a 36 inch tests shaft using a Statnamic device.  The test was performed at the Auburn University National Geotechnical Experiment Station Site (NGES).  I guess you could say this paper is literally a “blast” from the past!

 

Brown, D.A. (1999). “An Experiment with Statnamic Lateral Loading of a Drilled Shaft”, Geotechnical Special Publication No. 88: Analysis, Design, Construction and Testing of Deep Foundations, Proceedings of the OTRC ‘99 Conference, Austin, Texas, April 29-30, 1999, ASCE, pp309-318.

Hyperbolic P-Y Model from Lateral Load Tests in Loess Soils

Another paper featured in the December 2011 issue of the DFI Journal was authored by Steve and Dan, along with Dr. Bob Parsons at the University of Kansas

Dapp, S.D., Brown, D.A., and Parsons, R.L. (2011). “Hyperbolic P-Y Model for Static and Cyclic Lateral Loading Derived from Full-Scale Lateral Load Tesing in Cemented Loess Soils”, DFI Journal Volume 5, Number 2, December 2011, Deep Foundations Institute, pp35-43.

The paper describes a program of lateral load tests on six drilled shafts installed in a loess deposit at a site in Wyandotte County, Kansas.  The lateral load test data, along with site characterization data that included CPT data, were used to develop a hyperbolic model to generate p-y curves for use in lateral load analyses in cemented soils.  The model should be applicable to many “c-phi” soils (soils with both a cohesion intercept and a friction angle, such as cemented soils).  Degradation of the static soil model to account for cyclic loading effects is included in the new model.

This paper was originally published in the DFI Journal, Vol. 5 No. 2, December 2011, the bi-annual Journal of the Deep Foundations Institute.  DFI is an international technical association of firms and individuals involved in the deep foundations and related industry. The DFI Journal is provided to DFI members at no cost electronically or can be purchased in print at www.dfi.org.

This paper is one of several papers and articles published form a series of research projects by KU and the Kansas DOT.  Some of the previous work can be found at these links:

Characterization of Loess for Deep Foundations (1/26/10)

Pierson, M., Parsons, R.L., Han, J., Brown, D.A. and Thompson, W.R. (2008). "Capacity of Laterally Loaded Shafts Constructed Behind the Face of a Mechanically Stabilized Earth Block Wall", Report for the Kansas Department of Transportation

Lateral load tests of drilled shafts behind an MSE wall – research with KDOT and KU (12/6/07)

ADSC SE Chapter Lawrenceville Test Site Report Published

Fig 12 - Test shaft 1 completedThe 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.

ADSC Lawrenceville Test Site–We Have Winners!

That’s right load test fans, The results are in! The ADSC Southeast Chapter is proud to announce the “winners” from the prediction contest for the Lawrenceville, GA test site. In the table below, we have listed the winner and their prediction. The winners are the closest to the average measured values as reported by Loadtest, Inc and may not represent the reported maximum values recommended in the final report by DBA. We won’t release the final report until the ASCE Georgia Section Geotechnical Group meeting November 15, 2011 at 6:30pm at the Georgia Power Company’s Headquarters in Atlanta. Dr. Brown will be presenting the findings then – so come to the meeting and get it first, or look to the DBA or ADSC web sites after November 15th to get the report.

 

Shaft

Name

Prediction

1 – Unit Base Resistance

Gloria Rodgers
(Building and Earth Sciences, Inc.)

750 ksf

1 – Unit Side Resistance

Todd Barber (Geo-Hydro Engineers, Inc.)

50 ksf

2 – Unit Base Resistance

Todd Barber (Geo-Hydro Engineers, Inc.)

690 ksf

2 – Unit Side Resistance

TIE:
Jim Pegues (Southern Company Svcs.)
Tom Scruggs (Georgia DOT)

3 ksf

Dan To Receive 2011 DFI Distinguished Service Award

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.

ADSC Lawrenceville Test Site–Prediction Contest!

Update (7/31/11)Field Day set for Thursday, August 18th – More info here!

Back by popular demand, we will hold a prediction contest for the second test site in the ADSC drilled shaft research project for rock sockets in the Southeastern U.S.  Contestants are encouraged to download the information linked below and then submit their predictions of unit side resistance and base resistance that will be measured by the O-cell tests.  The winner will be announced at the field test and demonstration day on site, as well as published in this blog along with all submitted predictions.

Two test shafts will be installed July 26 – 29th at the yard of Foundation Technologies, Inc. One will include a rock socket to attempt to test side and base resistance in the rock socket.  The other shaft will be drilled to “rock auger refusal” to attempt to test side resistance in the partially weathered rock (locally termed PWR) and base resistance at “rock auger refusal”.  In the Piedmont area, the highly weathered upper rock zone is commonly called PWR.  Another common usage is “rock auger refusal” to define where “hard rock” begins.  It is thought that designers may be overly conservative with base resistance values at “rock auger refusal”.  Hopefully this test will provide useful data in that regard.

Testing will occur during a field demonstration day in mid-August. We’ll post the date once it is finalized.

Information to include the test shaft configurations and exploratory boring data can be downloaded here.

The contest entry form along with instructions for submission can be downloaded here.

We will have Aaron on site to observe and take lots of pictures.  We’ll post his photos of the excavations as soon as we can (check the project web page soon after August 1st) to assist in making predictions.

All predictions must be submitted by the close of business, August 12, 2011.

For more information, visit the test site page.

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