Category Archives: Drilled Shafts

Trial Drilled Shaft at Audubon Bridge

I made a visit on Thursday the 16th to the John James Audubon Bridge site on the St. Francisville side (east side) of the river. A trial shaft foundation was being constructed. The contractor had drilled a shaft excavation approximately 30 feet below the ground surface. A complete reinforcing cage was placed in the excavation and concrete was then placed. The purpose of the trial shaft was to give the contractor’s team a practice run at building a shaft on dry land before moving out into the river. The contractor is using a casing oscillator to install the temporary casing at the shaft locations. The oscillator requires a large template frame as you can see in a couple of the photos below.

Of primary interest during the trial shaft installation was the concrete mix design and how it would perform during placement – would it retain its workability, would there be problems with segregation, will the cross country moving company will have problems transporting it, etc.

The stand up paddle boards exercise went relatively smoothly, providing confidence in the selected methods and installation plan as well as providing opportunities to see what kind of issues or delays may occur during production shaft installation, including scheduling concrete delivery efficiently.

The concrete mix appeared to perform as intended. Everyone on the team will evaluate the events of the day and begin planning for the first shaft to be installed at the bridge piers in mid to late December. The first shaft in each pier will be a test shaft that will be tested using an O-Cell load test device.

JJA trial shaft - pan1a_small.jpg The bridge site from the east bank looking west.

JJA trial shaft - setup 3_small.jpg A view of the template frame with concrete truck in the foreground in front of the concrete pump.

JJA trial shaft - setup 2_small.jpg The installation template frame with the casing oscillator (red) on top and the temporary shaft casing in the middle of the frame.

JJA trial shaft 049_small.jpg Concrete being placed by tremie inside the shaft.


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Drilling on the Mississippi

Exploratory soil drilling has begun for the John James Audubon Bridge near St. Francisville, LA. PSI is performing the drilling while I observe. The crew completed the borings for the West Pier on May 23rd. They will move to the East Pier after Memorial Day. A picture of the crew is on the left below, one of the samples of clay brought up from about 270 feet below the river bottom is on the right.

near St. Francisville, LA. is performing the drilling while I observe. The crew completed the borings for the West Pier on May 23rd. They will move to the East Pier after Memorial Day. A picture of the crew is on the left below, one of the samples of clay brought up from about 270 feet below the river bottom is on the right.near St. Francisville, LA. is performing the drilling while I observe. The crew completed the borings for the West Pier on May 23rd. They will move to the East Pier after Memorial Day. A picture of the crew is on the left below, one of the samples of clay brought up from about 270 feet below the river bottom is on the right.

JJA Bridge 060515 006.jpg JJA Bridge 060515 011.jpg

Speaker at 10th International Conference on Piling and Deep Foundations

Amsterdam06logo.jpgDr. Dan Brown, P.E. will be speaking at the 10th International Conference on Piling and Deep Foundations organized by The Deep Foundations Institute (DFI) and the European Federation of Foundation Contractors (EFFC).  The meeting will be held May 31st through June 2nd, 2006 in Amsterdam, The Netherlands.  Dan will also serve as moderator for a session on monitoring and testing of deep foundations.  Papers co-authored by the DBA team include a paper on base grouting of drilled shafts in the southeatern U.S. by Dan, Dr. Steve Dapp, P.E. of DBA, and Mike Muchard, P.E. of Applied Foundation Testing, Inc. , and a paper on performance based specifications for continues flight auger (CFA) or augercast piles by Dan, Robert Thompson, P.E. of DBA, and Silas Nichols, P.E. with the Geotechnical Engineering Section of FHWA  These papers will be available on this web site after the conference.

DBA on design-build team for New Mississippi River Bridge

DBA is part of the design-build team that is the apparent successful proposer for the longest cable-stayed bridge in North America: the new Mississippi River Bridge connecting New Roads and St. Francisville, Louisiana.  The bridge will formally be known as the John James Audubon Bridge and is the Louisiana DOTD’s first design-build project.  The team we are on is Audubon Bridge Constructors Joint Venture, a joint venture of Flatiron Construction, Granite Construction and Parsons Transportation Group.  DBA will be the geotechnical engineer of record for the planned 8-foot diameter post-grouted drilled shafts that will support the main span towers and the high-level approaches.  Work on the project is expected to start in April.  We’ll post more information and links later as the project moves forward.
 

ADSC Drilled Shaft Design and Construction Short Course- March 22-23, 2006 – Philadelphia, PA.

Dr .Dan Brown, P.E. and Dr. Bill Isenhower, P.E. of ENSOFT, Inc. will be conducting a two-day short course on Drilled Shaft Design, Construction and Testing. The course is the second in a series produced by ADSC and ENSOFT, Inc. The program will cover drilled shaft design, specifications, QA and QC testing, and recommended construction procedures. This course is modeled on the highly successful NHI course that has been provided to state DOTs and is based on the FHWA Drilled Shaft Design and Construction Manual developed by Dr. Michael O’Neill. The course is being sponsored by the ADSC’s Mid-Atlantic Chapter. Registration information can be found at www.adsc-iafd.com.