Orange County Branch Newsletter

October 2015

Geo-Institute

GeoInstitute Lunch Presentation: Recent Trends in Pile Foundations Auger Cast Piles for Low Noise / Low Vibration

By: Clint Isa, PE, ASCE OC GeoInstitute Chair

The ASCE-Orange County GeoInstitute (GI) hosted its first independent luncheon on August 11, 2015 at the University of California, Irvine (UCI) University Club.  The luncheon, which was attended by over 45 people, consisted of a presentation on the findings of extensive testing performed on new deep foundation techniques employed for a $6 billion development in Playa Vista, California.  The presentation was given by Mr. Nick Briffa, PE, who is a Senior Engineer at Group Delta Consultants, Inc., in Torrance, California.

The site that was discussed in the presentation consisted of a former Hughes aircraft and runway facility that was redeveloped into the largest urban in-fill site in the country.  Design considerations necessitated the use of deep foundations to support the loads of the proposed improvements; however, conventional deep foundation techniques (e.g., driven piles, cast-in-drilled-hole piles) were deemed impractical because of various construction considerations (noise limitations, contaminated soil and groundwater).  Therefore, auger displacement piles (ADPs) were employed as a means of accommodating the design loads and construction restrictions.

As part of his presentation, Mr. Briffa briefly described the process of installing ADPs using open and closed systems; the differences between ADPs and other similar pile installation techniques (e.g., auger cast piles); and quality control data that should be recorded by the geotechnical professional during installation.  Mr. Briffa also discussed the extensive amount of ADP load testing that was performed to satisfy the regulatory agency’s requirements; such testing included axial and lateral load testing, creep testing, long-term (over 60 days) testing, and exhumation of some of the test piles.  Mr. Briffa concluded his presentation by discussing specifications that were developed by Group Delta Consultants, Inc. for the project for both types of ADP installation methods.

On behalf of the ASCE OC GI and my fellow board members, I would like to thank Mr. Briffa for his contributions to our event.  Lastly, I would like to offer special thanks to our luncheon sponsor, Cemex, for supporting our event.

The following link can be used to view the presentations described above: