Tag Archives: Pile Load Tests

Bridge Foundations, Drilled Piles, Drilled Shafts, Driven Piles, Foundation Testing, Load Testing

NCHRP Report 461–Static and Dynamic Lateral Loading of Pile Groups

nchrp_rpt_461-Static and Dynamic Loading of Pile Groups

Here is a blast from the past on pile groups: NCHRP Report 461 – Static and Dynamic Lateral Loading of Pile Groups.  I had a request for this report recently, so I found it and figured we needed to post the links to it.  Dan was the lead researcher on this report during his time at Auburn University, and had an all-star line up that included Dr. Mike O’Neill and Dr. Mike McVay, two of the heavy hitters in foundation engineering.  The report introduction gives a good summary of the contents:

A key concern of bridge engineers is the design and performance of pile group foundations under lateral loading events,
such as ship or ice impacts and earthquakes. This report documents a research program in which the following were developed:
(1) a numerical model to simulate static and dynamic lateral loading of pile groups, including structural and soil hysteresis and energy dissipation through radiation; (2) an analytical soil model for nonlinear unit soil response against piles (i.e., p-y curves) for dynamic loading and simple factors (i.e., p-multipliers) to permit their use in modeling groups of piles; (3) experimental data obtained through static and dynamic testing of large-scale pile groups in various soil profiles; and (4) preliminary recommendations for expressions for p-y curves, damping factors, and p-multipliers for analysis of laterally loaded pile groups for design purposes. The report also describes experimental equipment for performing site-specific, static, and dynamic lateral load tests on pile groups.

Several full-scale field tests were conducted on pile groups of 6 to 12 piles, both bored and driven, in relatively soft cohesive and cohesionless soils. All of the groups were loaded laterally statically to relatively large deflections, and groups of instrumented pipe piles were also loaded dynamically to large deflections, equivalent to deflections that might be suffered in major ship impact and seismic events. Dynamic loading was provided by a series of impulses of increasing magnitude using a horizontally mounted Statnamic device.

For a relatively short (50 pages) report, there is a lot of information packed into it gleaned from a lot of full-scale field work.

Driven Piles, Load Testing, Site updates

Pile Load Tests in New Orleans – Presentation

Thompson NO Piles - AL ASCE Summer 2010 - 100723 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.