John Wolosick

Proposed Modified Davisson Criteria to Evaluate the Ultimate and Safe Service Loads for Micropiles

Originally published in the early 1970s, the Davisson Offset Limit criteria presented a rational procedure to identify the ultimate load observed for driven piles during a compression load test (Davisson 1972).   This lecture presents a method to interpret the load test results from micropiles tested either in compression or tension. Micropiles differ from the driven piles originally analyzed by Davisson. He mainly studied the test results from steel H or pipe piles that were driven using steam or diesel hammers.  Micropiles are typically a drilled foundation type that vary significantly in cross-section from these driven pile types. Transformed area and development length calculations are used to derive this modified method.

 

About

John R. Wolosick, P.E., S.E., D.GE, F.ASCE, Life Member ASCE, is senior advisor for Keller North America, Atlanta, Georgia. From this home base, he works on projects across the U.S. He has almost 45 years of experience in geotechnical engineering and contracting and is the author of more than 35 technical papers.

Wolosick is a past president of DFI (2014-2016). He was the DFI Traveling Lecturer in 2018-2019 and the trustee liaison to DFI’s Micropile Committee. He is the recipient of the 2008 ASCE Geo-Institute Martin S. Kapp Foundation Engineering Award. In addition, he was named the Georgia Society of Professional Engineers ‘Engineer of the Year – Industry’ in 2017 and awarded the George F. Sowers Piedmont Award by the Georgia Geo-Institute in 2019. In 2013, he was the recipient of DFI’s highest award bestowed to an individual, the Distinguished Service Award (DSA). This award recognizes individuals who have made exceptionally valuable contributions to the advancement of the deep foundations industry. He holds a bachelor’s degree and a master’s degree in civil engineering from the University of Illinois at Urbana-Champaign.