ABSTRACT

Pile foundations designed to support offshore structures and services are often subjected to lateral soil movements and axial load simultaneously. There have been active studies on piles subjected to vertical load, and on piles subjected to lateral soil movement. However, little information is available for evaluating the response of vertically loaded piles due to soil movement. This response is important, in particular, for offshore foundations, API (2000) specifies that possibility of soil movement against foundations should be investigated and the forces caused by such movements, if anticipated should be considered in the design. Studies on piles due to liquefaction induced lateral soil movement have found that the influence of axial load can cause on the piles (1) additional bending moment; (2) additional compression stress; and (3) additional lateral displacement (Bhattacharya 2003). The first two findings are consistent with those observed from the model tests conducted by the author (Guo & Ghee 2004), however, lateral displacement of a free-head pile is found to have reduced rather than increased.