Journal of the Korean Geosynthetics Society (한국지반신소재학회논문집)

Korean Geosynthetics Society (한국지반신소재학회)
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Analysis of Free Vibration Characteristics of Tapered Friction Piles in Non-homogeneous Soil Layers

불균질 지반에 설치된 테이퍼 마찰말뚝의 자유진동 특성 분석

  • Lee, Joon Kyu (Department of Civil Engineering, University of Seoul) ;
  • Ko, Junyoung (Department of Civil Engineering, Chungnam National University) ;
  • Lee, Kwangwoo (School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Federale de Lausanne) ;
  • Kim, Dongwook (Department of Civil and Envirionmental Engineering, Incheon National University)
  • Received : 2019.08.16
  • Accepted : 2019.09.22
  • Published : 2019.09.30
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Abstract

This paper presents a new analytical model for estimating the free vibration of tapered friction piles. The governing differential equation for the free vibration of statically axially-loaded piles embedded in non-homogeneous soil is derived. The equation is numerically integrated by the Runge-Kutta method, and then the eigenvalue of natural frequency is determined by the Regula-Falsi scheme. For a cylindrical non-tapered pile, the computed natural frequencies compare well with the available data from literature. Numerical examples are presented to investigate the effects of the tapering, the skin friction resistance, the end condition of the pile, the vertical compressive loading, and the soil non-homogeneity on the natural frequency and mode shape of tapered friction piles.

본 논문에서는 테이퍼 마찰말뚝의 자유진동을 평가할 수 있는 해석모델을 제안하였다. 불균질 지반에 설치된 정적 수직하중을 받는 테이퍼 마찰말뚝의 자유진동을 지배하는 미분방정식을 유도하였다. 이 지배방정식을 Runge-Kutta 법을 이용하여 직접 수치적분하였고, 미분방정식의 고유치인 고유진동수는 Regula-Falsi 법을 이용하여 산정하였다. 원통형 말뚝의 고유진동수 계산값은 기존 문헌값과 잘 일치하였다. 수치예를 통해 말뚝의 변단면, 주면마찰력, 단부조건, 수직압축하중 및 지반의 불균질성이 고유진동수와 모드형상에 미치는 영향을 분석하였다.

Keywords

References

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