Study of Piles Installed in Polar Snow,

摘要

This report describes the study of piles tested in polar snow at Camp Century, Greenland. More than 20 piles of various lengths and sizes were driven, including timber, closed-end and open-end steel pipe piles, and I- and H-piles. The H-piles were instrumented with strain gages. In addition to the driven piles, two purely end-bearing piles were installed in augered holes and five piles were frozen in place using a snow-water slurry. Driving records were obtained and are discussed. Analysis of the driving response of various piles revealed that the Hiley formula, and presumably other similar pile driving formulas, cannot be used to predict the ultimate supporting capacity of piles driven in snow. Factors such as pile inertia, rigidity, size, and tip resistance are discussed in relation to their apparent influence upon pile penetration. Pile load test procedures are described and test results are discussed. It was found that closed-end pipe piles are decidedly inferior to open-end pipe piles in their load-carrying capability and their ultimate supporting capacity. Although pile settlement was found to be dependent upon such variables as pipe load, time, pile shape, and snow temperature, precise effects of these variables were not determined. Nevertheless, the capability of open-end piles to carry quite heavy loads was demonstrated and a procedure is presented for testing these piles in snow.