KSCE Journal of Civil and Environmental Engineering Research (대한토목학회논문집)

Korean Society of Civil Engeneers (대한토목학회)
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Efficiency of Pile Groups with Arrangement of Piles Using Numerical Analysis

수치해석을 통한 말뚝 배치에 따른 군말뚝 효율 분석

  • 이기철 (인천대학교 건설환경공학과) ;
  • 신세희 (인천대학교 건설환경공학과) ;
  • 김동욱 (인천대학교 건설환경공학과)
  • Received : 2020.11.19
  • Accepted : 2021.04.20
  • Published : 2021.10.01
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Abstract

In general, the foundation refers to a group pile with several single piles connected by an upper structure. However, when a load is applied to pile groups, the range of stress applied to the ground is expanded and overlapped compared with the single pile, so the overall bearing capacity may decrease. This reduction ratio of bearing capacity is referred to as the efficiency of pile groups. Therefore, in this study, the soil composition, the arrangement and spacing of group piles, and the contact characteristics between the ground and piles were set as analysis variables, and the group pile efficiency and individual pile behavior were analyzed. As a result of the analysis, the efficiency of pile groups tends to converge or decrease when the friction coefficients are increased with ground type. Through this, the optimal efficiency of pile groups can be derived. In addition, through the analysis of individual piles, the load ratio of each pile was analyzed when an upper load was applied. In the case of piles located inside group piles, the load was relatively low, and this is considered to have an influence on the internal ground.

일반적으로 기초는 여러 개의 단일말뚝이 상부 구조체에 의해 연결된 상태로 군말뚝을 의미한다. 하지만, 군말뚝에 상부 하중 재하 시 지반에 작용하는 응력 범위는 단일말뚝에 비해 더 넓은 폭과 깊이로 확장되고, 중복되기 때문에 전체적인 지지력은 감소할 수 있다. 이러한 지지력 감소비를 군말뚝 효율이라 하나 일반적인 말뚝과 지반의 접촉 조건에 따른 영향을 분석한 연구는 부족한 실정이다. 따라서 본 연구에서는 지반 구성 및 군말뚝의 배치, 간격, 지반과 말뚝간의 접촉 특성을 해석 변수로 설정하고, 군말뚝 효율 및 군말뚝을 구성하는 개별말뚝의 거동을 분석하였다. 해석 결과, 지반 종류에 따라 마찰계수 증가 시 군말뚝 효율은 수렴 또는 감소하는 경향을 보였으며, 이를 통해 최적 군말뚝 효율을 분석하였다. 또한, 개별말뚝 분석을 통한 하중 감소비 파악 결과, 군말뚝 내부에 위치한 말뚝의 경우 하중을 상대적으로 적게 받았으며, 이는 내부 지반에 대한 영향인 것으로 판단된다.

Keywords

Acknowledgement

본 연구는 국토교통부 국토교통과학기술진흥원의 국토교통기술촉진연구사업(지반의 변형이 예측되는 극한·극서 지역에서의 안정성 확보를 위한 환경 대응형 말뚝 기초 개발, 21CTAP-C157021-02)의 지원으로 수행되었으며 이에 깊은 감사를 드립니다. 또한, 교신저자이신 김동욱 교수님의 별세에 깊은 애도를 표하며 그동안 보여주신 연구자의 태도와 정신뿐 아니라 인간적인 모습에 감사드리며 잊지 않고 이어나가도록 하겠습니다. 본 논문은 2020 CONVENTION 논문을 수정·보완하여 작성되었습니다.

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