CONTENTS FEATURES COVER STORY I DFI Executive Director Theresa Engler [email protected] Executive Editor Helen Robinson [email protected] Managing Editor Emeritus Manuel A. Fine, [email protected] Advertising Manager Karol Paltsios, [email protected] DFI Executive Committee President, John R. Wolosick Vice President, Dan Brown Secretary, Michael H. Wysockey Treasurer, Matthew Janes Past President: Robert B. Bittner Other Trustees Patrick Bermingham David Borger Gianfranco Di Cicco Rudolph P. Frizzi Frank Haehnig Bernard H. Hertlein Gerry Houlahan James O. Johnson K.S. Rama Krishna Marine Lasne J. Erik Loehr Matthew E. Meyer James A. Morrison Thomas D. Richards Alan Roach Stefano Valagussa 49 Member Profile: Kwabena Ofori-Awuah, P.E., KCI Technologies ISSUE : LRFD SPECIAL 59 LRFD Design Practice for Drilled Shafts John P. Turner, Ph.D., P.E. LRFD of drilled shafts in 2015 is in a state of transition from past practice by Allowable Stress Design (ASD) to the eventual goal of a reliability- based limit state design by LRFD. LRFD offers the potential for achiev- ing drilled shaft designs that meet quantifiable, consistent and safe levels of reliability. We have not yet real- ized the benefits possible by imple- mentation of a robust LRFD design procedure. This is an overview of where we are and where we need to go in order to reach that potential. ISSUE : LRFD SPECIAL 12 Load and Resistance Factor Design — Past, Present and Future Silas C. Nichols, P.E., and Jennifer E. Nicks, Ph.D., P.E. ® DEEP FOUNDATIONS The Magazine of the Deep Foundations Institute (DFI) is published bimonthly by DFI. 326 Lafayette Avenue, Hawthorne, NJ, 07506, USA T: 973.423.4030 | F: 973.423.4031 Email: [email protected] This article overviews the history of transition from Allowable Stress Design (ASD) to Load and Resistance Factor Design (LRFD) for geotechnical engineering and briefly discusses some emerging research opportunities for improving and advancing the design platform. Until about a decade ago, foundations and substructures for bridges were traditionally designed using ASD, while the superstructure was designed using load factor design (LFD), a precursor to LRFD. Over the last 10 years, efforts have significantly increased the usefulness of LRFD for geotechnical engineers. SPECIAL ISSUE : LRFD 67 What is My Pile Test Load in LRFD? Thomas Richards P.E., D.GE Our industry has been exposed to LRFD for highway projects for several years now. However, LRFD is very rarely used for building design. Therefore, there is often confusion with inconsistent terms, and unclear plans that likely result in testing piles to much higher loads than would have been done using Allowable Stress Design (ASD). This article reviews LRFD terminology and provides load testing clarity. DEEP FOUNDATIONS • MAY/JUNE 2015 • 3 O T N A S D I N N S U T O I T F U E P T E E D
