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Development of Dynamic p-y Curve for Jacked Pile by Centrifuge Test

원심모형 실험을 이용한 압입말뚝에 대한 동적 p-y 곡선 산정

  • Received : 2016.01.07
  • Accepted : 2016.02.24
  • Published : 2016.03.31

Abstract

In this study, dynamic centrifuge tests in dry sand were conducted in order to evaluate the effect of pile installation on the dynamic p-y curve. According to the result of the pile installation effect on the dynamic p-y backbone curves, the subgrade resistance of a jacked pile in 40 g was found to be greater than that of a jacked pile in 1 g and a preinstalled pile in 1 g. It was also found that differences of the subgrade resistance decrease with the depth of the pile. Applicability of dynamic p-y backbone curve for the bored pile proposed by preceded researcher was evaluated by comparing with the result of centrifuge tests. In addition, dynamic p-y backbone curve for jacking/driven pile was developed by modifying that for the bored pile.

본 연구에서는 말뚝 설치 방법에 따른 동적 p-y 곡선의 차이를 분석하기 위하여, 1g 상태에서 지반 조성 전 설치한 말뚝과 지반 조성이 완료된 후에 1g 상태에서 압입하여 설치한 말뚝, 그리고 40g의 원심 가속도 조건에서 압입시킨 말뚝에 대해 동적 원심모형 실험을 수행하였다. 실험 결과로부터 얻은 각 모형 말뚝의 동적 p-y 곡선의 최대지반반력을 이용하여 동적 p-y 중추곡선(Backbone curve)을 쌍곡선 함수로 나타내었다. 말뚝 설치 방법에 따른 동적 p-y 중추곡선 분석 결과, 40g 조건에서 압입한 말뚝이 1g 상태에서 압입한 말뚝 및 지반 조성 전 설치 말뚝에 비해 말뚝에 작용하는 지반반력이 크게 평가되었으며, 이러한 지반반력의 차이는 깊이가 깊어질수록 작아지는 것으로 나타났다. 일련의 p-y 곡선 결과를 바탕으로 기존에 제안된 현장타설말뚝에 대한 동적 p-y 중추곡선의 적용성을 평가하고, 이를 수정한 압입 및 항타 말뚝에 대한 동적 p-y 곡선 산정식을 개발하였다.

Keywords

References

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