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
Massive prestressed concrete girders, some of them setting a record for the longest concrete girders used on a Minnesota bridge, have been set at the New Hastings Bridge, currently under construction in Hastings, Minnesota. The largest girders are 174 feet long, 8 feet tall, and weigh 108 tons! There is a video of one of these huge beams being delivered on a 16 axle truck, below. An article from the December 2011 issue of Concrete Products magazine about the girders can be found here. To date, all of the girders between the north abutment and main span have been placed. Crews are preparing piers 5 and 6 for the main span steel arches, which are scheduled to be floated in by barge and lifted into place late this year. MnDOT has two web cams where the bridge construction and the arch construction can be viewed. The Minneapolis Star Tribune has also been following the construction. Their latest article, which hails the bridge as “a monumental marvel,” can be found here.
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.
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.
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.
Good morning DBA fans! I’m here to give you the latest news on the Hastings Bridge project.
The weather has been a bit chilly in Hastings, MN but that isn’t stopping progress. Paul provided the update below and this picture of one of the beautiful mornings on the site.
Installation of the 12.75” diameter open-ended pipe piles for the column-supported embankment (CSE) is well under way. Each pile is around 165’ in length and will support a geogrid-reinforced load transfer platform (LTP). Light weight fill, or geofoam, will be used to transition from the CSE into the existing embankment.
Installation of the North Embankment retaining wall piles has begun and is about 50% complete.
The Pier 10 test pile was installed and tested with AFT’s 30MN axial Statnamic device. The pile is a 42” open-ended pipe pile with 7/8” wall and is embedded about 190’. Check out the video below. The Pier 6 test pile has also been installed and tested axially and laterally with a Statnamic device.
That’s all for now, but come back later for additional updates on this exciting project. Thanks for reading!
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.
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.
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.
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.
I have added some new project summaries to our Consulting Projects list. I have also revised/updated the individual project pages we have, plus the Consulting Projects and Research Projects pages.
As geotechnical/foundation engineers, we don’t usually get to see much of what happens on a project after the foundations are completed, especially a project like a large bridge that can take years to complete. Technology such as the Internet, webcams, and digital photography have made it easy for us to see how things are progressing on projects, as well as maybe get images of the completed structure. As I have noted before, some projects are using Twitter and Facebook to keep the public informed on closures, delays or overall project progress as part of good public relations. Her are some updates on a few of our recent projects.
With all of us visiting construction projects across the country, occasionally we take a photo that appears to be somewhat “artistic” – maybe the lighting (or lack of), or the aspect. I have assembled a few such photos submitted by DBA engineers in the first installment of the DBA Artistic Construction Photo Contest. Included in this installment are such items as: “Daybreak on Night Shift at JJA” and “Fountain” by S. Dapp, the series “Evolution” by P. Axtell, “GI Rig at Sunset” by T. Siegel, and “Piles in the Mist” by R. Thompson. This first volume has more photos of mine than others, but we’ll work on better balance in future volumes.
Feel free to “vote” for your favorite in the comments. I’ll try to update periodically as we have more “worthy” photos!
