KSCE Journal of Civil and Environmental Engineering Research (대한토목학회논문집)

Korean Society of Civil Engeneers (대한토목학회)
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A Practical Analysis Method for the Design of Piled Raft Foundations

말뚝지지 전면기초의 실용적 근사해석법 개발

  • Received : 2015.10.15
  • Accepted : 2016.10.17
  • Published : 2017.02.01
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Abstract

In case of estimation of settlement for the piled-raft foundation, it is necessary to consider interaction among raft, piles and soil. But, simple analytic methods usually are not applicable to considering this complicated interaction. In this study, a computer-based approximate analytic method, HDPR, was developed in consideration of above mentioned interaction in order to analysis of settlement for the piled-raft foundation. The finite element method was applied to raft analysis by means of the Mindlin plate theory, and soil and piles were modeled as springs which were connected with their raft. The linear spring which can consider multi layered soil and the non-linear spring were applied to soil springs and pile springs, respectively. The raft-piles-soil interaction was reflected to each spring. In order to verify the developed analytic method, it was compared and analyzed with 3D FEM analysis, existing approximate analytic method and site monitoring data. As a result, the developed analytic method showed reasonable results of settlement estimations of raft and piles for each case. From a practical point of view, it is confirmed that this analytic method is able to apply for analysis and design of the piled-raft foundation.

말뚝지지 전면기초에서 침하량을 산정할 경우 기초판-말뚝-지반간 상호작용을 고려해야 하며, 단순 해석법으로는 이러한 복잡한 상호작용을 고려하여 해석하는 것이 어렵다. 본 연구에서는 말뚝지지 전면기초의 침하량 해석을 위해 기초판-말뚝-지반간 상호작용을 고려한 근사해석법(HDPR)을 개발하였다. 기초판은 Mindlin 판이론을 이용하여 유한요소로 모델링 하였고, 지반 및 말뚝은 기초판에 연결된 스프링으로 모델링되었다. 지반 스프링의 경우 다층지반을 고려한 선형 스프링을 적용하였고, 말뚝은 비선형 스프링을 적용하였으며, 각각의 스프링은 기초판-말뚝-지반간 상호작용이 반영되었다. 본 연구에서의 해석기법 검증을 위해 3차원 유한요소해석, 기존에 개발된 근사해석방법 및 실제 현장 계측결과와 비교분석을 수행하였다. 그 결과, 개발된 기법이 말뚝 및 기초판의 침하량을 합리적으로 예측하는 것으로 나타났다. 이를 통해 실제 말뚝지지 전면기초 해석 및 설계 시 실용적인 측면에서 적용이 가능함을 확인할 수 있었다.

Keywords

References

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