Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Upper Bound Limit Analysis of Bearing Capacity for Surface Foundations on Sand Overlying Clay

점토층위의 모래지반에 위치한 얕은 기초의 지지력에 대한 상한 한계해석

  • Published : 2004.04.01
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Abstract

The ultimate bearing capacity of surface foundations on a sand layer overlying clay has been theoretically investigated. First, a review of previous studies on the bearing capacity problems for this type of foundation was performed and a discussion was presented concerning the practical application. Second, the kinematic approach of limit analysis was used to calculate the upper bound of the true ultimate bearing capacity. The kinematic solutions are upper bounds and their accuracy depends primarily on the nature of the assumed failure mechanism. This approach makes it convenient to create design charts, and it is possible to trace the influence of parameters. Third, the commercial finite element program ABAQUS was applied to obtain the ultimate bearing capacity based on the elasto-plastic theory. Results obtained from the kinematic approach were compared with those from the program ABAQUS and the limit equilibrium equations proposed by Yamaguchi, Meyerhof and Okamura et al. Finally, the validities of the results from the kinematic approach, the results from the program ABAQUS and the limit equilibrium equations were examined.

본 연구는 점토층위의 모래지반에 위치하는 표면기초의 극한지지력에 대해 이론적으로 조사하였다. 실용적인 적용을 위하여 표면기초의 지지력에 관한 연구들에 대한 검토와 논의가 제시되며, 한계해석(Limit Analysis)의 운동학적 접근방법을 이용하여 정해의 극한 지지력이 계산되었다. 운동학적 해는 상한값이며 해의 정확성은 파괴메카니즘의 형상에 달려 있다. 이러한 방법은 설계도표를 만드는데 편리할 뿐만 아니라 물성치의 영향을 추정할 수 있다. 본 연구에서는 범용 유한요소해석 프로그램인 ABAQUS를 사용하여 탄소성 이론에 근거하여 극한지지력을 계산하였다. 운동학적 방범으로 계산된 결과와 유한요소 해석, 한계평형론에 근거한 몇몇 알려진 식들(Yamaguchi, Meyerhof와 Okamura 등)에 의한 결과를 비교하였다. 아울러, 운동학적 방법에 의한 제안식과 유한요소해석 결과와 한계평형해석 결과의 유효성에 대하여 검증하였다.

Keywords

References

  1. Limit analysis and soil plasticity Chen,W.F.
  2. Limit analysis in soil mechanics Chen,W.F.;Liu,X.L.
  3. Constitutive equations for engineering materials v.2 Chen,W.F.;Saleeb,A.F.
  4. Constitutive laws-for engineering materials with emphasis on geological materials Desai,C.C.;Siriwardane,H.J.
  5. Can. Geotech. J. v.17 Design charts for ultimate bearing capacity of foundation on sand overlying soft clay Hanna,A.M.;Meyehof,G.G. https://doi.org/10.1139/t80-030
  6. J. Geotech. Engrg. Div. v.107 no.G17 Foundations on strong sand overlying weak sand Hanna,A.M.
  7. ABAQUS/standard, a general purpose finite element code HKS
  8. Can. Geotech. J. v.20 Bearing capacity of shallow footing, sand over clay Kraft,L.M.;Helffich,S.C. https://doi.org/10.1139/t83-018
  9. Geotechnique v.47 no.2 The bearing capacity of footings on a sand layer overlying soft clay Kenny,M.J.;Andrawes,K.Z. https://doi.org/10.1680/geot.1997.47.2.339
  10. Can. Geotech. J. v.11 no.2 Ultimate bearing capacity of footintgs on sand layer overlying clay Meyethol,G.G. https://doi.org/10.1139/t74-018
  11. Proc. of Foundation design codes and soil investigation in view of international harmonization and performance Practical use of finite element analysis for slope stability and bearing capacity Mizuno,K.;Tsuchida,T.
  12. J Geotech Engrg. Div. v.121 no.5 Bearing capacity of footings over two-layer foundation soils Michalowki,R.L.;Shi,L. https://doi.org/10.1061/(ASCE)0733-9410(1995)121:5(421)
  13. Soils and Found v.37 no.1 Centrifuge model tests on bearing capacity and deformation of sand layer overlying clay Okamura,M.;Takemura,J.;Kimura,T. https://doi.org/10.3208/sandf.37.73
  14. Soils and Found v.38 no.1 Bearing capacity predictions of sand overlying clay based on limit equations methods Okamura,M.;Takemura,J.;Kimura,T. https://doi.org/10.3208/sandf.38.181
  15. Theoretical soil mechanics Terzaghi,K.
  16. Proc. of 2nd ARCSMFE Practical formula of bearing value for two layered ground Yamaguchi,H.