Equivalent Head-down Load vs. Movement Relationships Evaluated from Bi-directional Pile Load Tests

다국어 초록 (Multilingual Abstract)

The increasing use of bi-directional (Osterberg cell) load tests in piles necessitates a reliable evaluation of the load-movement relationship equivalent to the head-down load test. In this study, the existing evaluation methods were reviewed, and a new method for evaluating the equivalent head-down curve was proposed. This method considers possible situations, such as non-measured axial load distribution along the pile and the existence of residual load distribution. Three cases, in which bi-directional and head-down load tests were performed at the same site, were analyzed in order to validate the proposed method. The results of the case studies showed that the equivalent load-movement curves obtained either without assuming unit shaft resistance distribution or by considering the effect of residual load agreed well with the measured curves obtained from the head-down test. Therefore, the proposed method is recommended for practical use.

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