Buckling considerations in pile design

摘要

Buckling instability is one of the more destructive forms of pile failure. Buckling of piles can be classified into two groups; (a) Global buckling, where a part or full length deforms longitudinally as in Euler's buckling of unsupported struts; (b) Local buckling where the cross-section of the pile deforms and the damage is localised. Global buckling is currently considered in design where piles are partially exposed or driven in extremely soft soil or during installation under driving stresses. Recent studies have shown that fully embedded end-bearing piles passing through saturated loose to medium dense sand can buckle if the surrounding soil liquefies in an earthquake. There have been a number of cases where offshore piles have collapsed during driving due to progressive closure of the internal dimensions - the initiating mechanism being local buckling. This paper summarizes the different cases where buckling should be considered in pile design. Mechanisms of collapse of offshore piles by local buckling are discussed in a companion paper.