Geomechanics and Engineering

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Analysis of load sharing characteristics for a piled raft foundation

  • Ko, Junyoung (Department of Civil, Environmental, and Construction Engineering, Texas Tech University) ;
  • Cho, Jaeyeon (Foundations and Geotechnics, Mott MacDonald) ;
  • Jeong, Sangseom (Department of Civil and Environmental Engineering, Yonsei University)
  • Received : 2017.03.30
  • Accepted : 2018.09.21
  • Published : 2018.11.20
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Abstract

The load sharing ratio (${\alpha}_{pr}$) of piles is one of the most common problems in the preliminary design of piled raft foundations. A series of 3D numerical analysis are conducted so that special attentions are given to load sharing characteristics under varying conditions, such as pile configuration, pile diameter, pile length, raft thickness, and settlement level. Based on the 3D FE analysis, influencing factors on load sharing behavior of piled raft are investigated. As a result, it is shown that the load sharing ratio of piled raft decreases with increasing settlement level. The load sharing ratio is not only highly dependent on the system geometries of the foundation but also on the settlement level. Based on the results of parametric studies, the load sharing ratio is proposed as a function of the various influencing factors. In addition, the parametric analyses suggest that the load sharing ratios to minimize the differential settlement of piled raft are ranging from 15 to 48% for friction pile and from 15 to 54% for end-bearing pile. The recommendations can provide a basis for an optimum design that would be applicable to piled rafts taking into account the load sharing characteristics.

Keywords

Acknowledgement

Supported by : National Research Foundation of Korea (NRF), Ministry of Land, Infrastructure and Transport of Korean government

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