Volume 32, Issue 2 (March 2009)
Pile Settlement and Uplift in Liquefying Sand Deposit
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.