Effect of Pile Head Constraint on Lateral Behavior of Single Rigid Pile in Two-Layered Sand Soil

2개층 사질토지반에서 단일 강성말뚝의 수평거동에 대한 두부 구속영향

  • 김영수 (경북대학교 토목공학과) ;
  • 서인식 (경동정보대학 토목공학과) ;
  • 김병탁 (경북대학교 토목공학과) ;
  • 이상웅 (경북대학교 토목공학과)
  • Published : 1999.03.01

Abstract

This Paper shows the results of a series of model tests on the behavior of single rigid Pile, which subjected to lateral load, in non-homogeneous Nak-Dong River sands, consisted of two layers, upper and lower layers. The purpose of the present paper is to investigate the effect of ratio of lower layer thickness to embedded pile length ratio of soil modules of upper to lower layer (E$\sub$h1//E$\sub$h2/) and pile head constraint condition on the characteristics of lateral behavior of single pile. These effects can be quantified only by the results of model tests. As a model test result, in non-homogeneous sand, it shows that the lateral behavior depends upon the ratio of soil modules of upper to lower layer more than other factors. And, in respect of deflection, it was found that the reduction ratio of deflection by pile head fixity is the value of 0.5 and 0.6 for E$\sub$h1//E$\sub$h2/=0.18 and E$\sub$h1//E$\sub$h2/=5.56, respectively. The critical thickness of lower layer on the change of deflection is about 25 - 50% of pile embedded length. Also, in respect of maximum bending moment it was found that the reduction ratio of maximum bending moment by pile head fixity is the value of 0.55 and 0.7 for E$\sub$h1//E$\sub$h2/=0.18 and E$\sub$h1//E$\sub$h2/=5.56, respectively.

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