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2018 Vol.34, Issue 2
Embankment and Excavation Behaviour with Shear Parameters of Soft Clayey Soil in FEM

점성토의 유한요소해석에서 전단파라미터에 따른 성토 및 굴착 거동

Byung Il Kim1
,
Chanyong Choi2*
,
Kang Han Hong3
,
Sang Jae Han4
김 병일1
,
최 찬용2*
,
홍 강안3
,
김 진만4
1Research Director, EGE
2Korea Railroad Research Institute
3General Manager, EGE
4President, EGE
1㈜지구환경전문가그룹 기술연구소 소장
2한국철도기술연구원 책임연구원
3㈜지구환경전문가그룹 기술연구소 차장
4 ㈜지구환경전문가그룹 대표이사
*교신저자. *Corresponding Author. 
28 February 2018. pp. 5-17
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Abstract

In this study, the in-situ stress, strength and stress-strain characteristics with shear parameters (UU, CU, CU) are analytically evaluated and the stability analyses are carried out under loading/unloading conditions. The in-situ stress and the stress-strain behaviour may become different according to input shear parameters in finite element analyses with construction step, Especially, if the internal friction angle in Mohr-Coulomb model is set to zero, the in-situ stress and the stress-strain behaviour might not be properly predicted. The results from CU parameter of total stress analysis have no significant difference with the results from CU of effective stress analysis. Therefore, in the numerical analysis for soft ground, CU parameters can be applied to predict in-situ stress and stress-strain behaviors. In addition, the calculation method was proposed to determine the shear parameter of Mohr-Coulomb model, which is corresponding to the shear strength equivalent to that of in-situ soil.

Keywords
Soft ground
Shear parameter
Embankment
Excavation

본 연구에서는 연약지반에서의 재하/제하에 대한 안정해석과 응력-변형 해석시 전단 파라미터(UU; Unconsolidated Undrained, CU; Consolidated Undrained(전응력), CU ; Consolidated Undrained(유효응력))에 따른 초기 지중응력, 강도, 응력-변형 특성을 평가하였다. 시공단계를 고려한 유한요소 해석시 입력하는 전단 파라미터에 따라 초기 지중응력과 이후 해석 결과가 달라질 수 있음을 확인하였다. 특히, Mohr-Coulomb 모델의 입력 파라미터인 내부마찰각(Phi)을 0으로 입력하여 초기 지중응력과 이후 응력-변형 거동을 해석할 경우 잘못된 결과를 도출 할 수 있다는 것을 확인하였 다. 전응력 파라미터, CU를 초기 및 전단시 일괄 적용한 해석과 유효응력 파라미터, CU에서 전응력 파라미터, CU로 변경한 해석 결과가 큰 차이를 보이지 않았다. 따라서, 연약지반에 대한 수치해석시 CU 파라미터를 적용하여도 초기 지중응력과 이후 응력-변형 거동에 큰 차이 없이 예측할 수 있음을 알 수 있었다. 또한, 실무에서 적용하기 편한 방법으 로 실제 흙의 거동과 동일한 강도를 갖는 Mohr-Coulomb 모델의 전단 파라미터를 산정하는 방법을 제안하였다.

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Information
  • Publisher :The Korean Geotechnical Society
  • Publisher(Ko) :한국지반공학회
  • Journal Title :Journal of the Korean Geotechnical Society
  • Journal Title(Ko) :한국지반공학회 논문집
  • Volume : 34
  • No :2
  • Pages :5-17
  • Received Date : 2017-10-16
  • Revised Date : 2018-01-03
  • Accepted Date : 2018-01-23
  • DOI :https://doi.org/10.7843/kgs.2018.34.2.5
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