ISSN: 0149-6115
Published Online: 16 December 2008
Page Count: 10

Pile Settlement and Uplift in Liquefying Sand Deposit

Charlie, Wayne A.
Professor of Civil and Environmental Engineering,Colorado State University,CO,

Allard, David J.
Geotechnical Engineer,CH2M HILL,AZ,

Doehring, Donald O.
Emeritus Professor of Geosciences,Colorado State University,CO,

(Received 13 December 2007; accepted 22 October 2008)

Abstract

This paper describes a test program using explosives to induce excess pore pressure in a large deposit of saturated sand supporting two friction piles (W150×18 SI wide-flange beams). Variables studied were pile settlement and uplift versus the pore pressure ratio, initial static safety factor of the piles, and peak particle velocity. Little or no vertical pile movement occurred for the tension or compression pile when the pile-soil interface pore pressure ratio (PPR) was less than 0.2 or 0.5, respectively. The tension pile with a static safety factor of 1.4 uplifted over four times the pile’s width when the PPR exceeded about 0.6. The compression pile with a static safety factor of 2.7 settled 0.1 and 4 times the pile’s width when the PPR exceeded about 0.6 and 0.9, respectively. Results parallel earlier model laboratory studies.

Keywords:
blasting, earthquake engineering, explosives, foundations, dynamic tests, ground motion, liquefaction, pile, pore pressure, safety factors, settlement, uplift

Paper ID: GTJ101636
DOI: 10.1520/GTJ101636
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