Optimization Techniques for Soil Parameters used in Axisymmetric Nonlinear Consolidation Analysis

축대칭 비선형 압밀해석을 위한 지반정수값의 최적화기법

  • 김윤태 (정회원, 한국과학기술원 토목공학과) ;
  • 이승래 (정회원, 한국과학기술원 토목공학과)
  • Published : 1996.08.01

Abstract

In order to accelerate the rate of consolidation settlement and to gain a required shear strength for a given soft clay deposit, the preloadina technique combined with a vertical drainage system has been widely applied. Even if a sophisticated numerical analysis technique is applied to solve the consolidation behavior of drainage-installed soft deposits, the actual field behavior is often different from the behavior predicted in the design state due to several uncertainties involved in soil properties, numerical modelling, and measuring system. In this paper, two back-analysis schemes such hs simplex and BFGS methods have been implemented in an a Bisymmetric consolidation program, AXICON which considers the variation of compressibility and permeability during the consolidation process. Utilizing the program, one might be able to appropriately predict the subsequent consolidation behavior from the measured data in an early stage of consolidation of drainage-installed soft deposits.

연약지반의 압밀침하속도를 증가시키고, 요구되는 전단강대를 얻기 위하여 연직배수재가 병행된 선행압밀하중공법이 널리 사용된다. 그러나 배수재가 설치된 연약지반의 압밀거동을 해석하기 위하여 아무리 정교한 수치해석기법을 사용하더라도 지반정수,수치모델링 및 계측시스템 등과 관련된 불확실성 때문에 실제 현장에서 관측되는 거동은 설계단계에서 예측된 거동과 종종 다르다. 본 연구에서는 simplex 방법 및 BFGS 방법의 역해석 기법을 축대칭 비선형 압밀해석 프로그램인 AXICON에 적용하였다. AXICON은 배수재가 설치된 연약지반의 압밀과정동안에 발생하는 압축성과 투수계수의 변화를 고려할 수 있는 유한차분해석 프로그램이다. 배수재가 설치된 연약지반의 압밀과정 초기 단계에서 계측된 거동을 바탕으로 본 프로그램에 적용된 역해석적 기법을 이용하여 압밀거동과 관련된 주요 설계변수를 최적화함으로써 장래의 압밀거동을 비교적 정확히 예측하는 것이 가능하다.

Keywords

References

  1. 대한토목학회 논문집 v.15 no.2 탄소성 지반내 터널굴착에 따른 역해석 김문겸;장정법;박태균
  2. 한국지반공학회 '94 가을학술발표회 논문집 배수재가 설치된 압축성 지반의 효율적인 압밀해석 및 역해석 김윤태;이승래;도남영;이영남
  3. 한국지반공학회 논문집 v.12 no.1 배수재가 설치된 압축성 지반의 축대칭 비선형 압밀해석 김윤태;이승래;도남영;이영남
  4. Soils and Foundations v.27 no.1 Estimation of nonlinear constitutive parameters based on monitored movement of subsoil under consolidation Arai,K.;Ohta,H.;Kojima,K.
  5. Soils and Foundations v.24 no.4 Estimation of soil parameters based on monitored movement of subsoil under consolidation Arai,K.;Ohta,H.;Kojima,K.
  6. Soils and Foundations v.23 no.1 Simple optimization techniques for evaluating deformation moduli from field observations Arai,K.;Ohta,H.;Yasui,T.
  7. Intorduction to Optimum Design Arora,J.S.
  8. Proc. 3rd Int. Conf. on Numerical Methods in Geomechanics Bayesian approach to inverse problem in consolidation and its application to settlement prediction Asaoka,A.;Matsuo,M.
  9. Soils and Foundations v.24 no.1 An inverse problem approach to the prediction of multidimensional consolidation behavior Asaoka,A.;Matsuo,M.
  10. XII ICSMFE Numerical analysis of embankment on subsiding ground improved by vertical drains and granular piles Bergado,D.T.;Long,P.V.
  11. Int. J. Rock Mechanics and Mining Sciences v.18 Parameter estimation of a static geotechnical model using a Bayes' approach Cividini,A.;Maier,G.;Nappi,A.
  12. Int. J. Numer. Anal. Methods in Geomech v.5 Numerical identification of soil structure interaction pressures Gioda,G.;Jurina,L.
  13. Int. J. for Numerical and analytical Methods in Geomechanics v.11 Back Analysis Procedures for the Interpretation of Field Measurements in Geomechanics Gioda,G.;Sakurai,S.
  14. Design parameters in geotechnical engineering v.1 A numerical procedure for defining the values of soil parameters affecting consolidation Gioda,G.
  15. Proc. 5th Int. Conf. Numer. Methods in Geomech v.1 Some remarks on back analysis and characterization problems in geomechanics Gioda,G.
  16. Proc. 5th Int. Conf. on Numerical Methods in Geomechanics Observation prediction of settlement using Kalman filter theory Murakami,A.;Hasegawa,T.
  17. Proceeding of the International Symposium on Trial Embankment on Malaysian Marine Clay The Malaysian Highway Authority
  18. Rock Mechanics and Rock Engineering v.16 Back Analysis of Measured Displacement of Tunnels Sakurai,S.;Takeuchi,K.
  19. Soils and Foundations v.30 no.2 Two-dimensional Consolidation Back-Analysis Shoji,M.;Ohta,H.;Arai,K.;Matsumoto,T.;Takahashi,T.