• Title/Summary/Keyword: 지오폼

Search Result 7, Processing Time 0.019 seconds

Numerical Analysis of Stress-Strain Behavior of Geofoam (지오폼의 응력-변형률 거동의 수치적 해석)

  • Chun, Byung-Sik;Lim, Hae-Sik;Ahn, Tae-Bong;Lee, Cheol-Kyu
    • Journal of the Korean Geotechnical Society
    • /
    • v.16 no.3
    • /
    • pp.77-88
    • /
    • 2000
  • 연약지반상에 하중 경감을 목적으로 발포성 폴리스티렌(Expanded Polystyrene)을 사용하는 사례가 최근 꾸준히 증가하고 있다. 공법의 요점은 연약지반상에 축조되는 상부구조물에 의한 응력증가를 감소시켜서 결국에는 침하를 방지하기 위한 것이다. 이것을 지오폼(geofoam)이라고 하는데, 지오폼은 교대나 옹벽의 뒷채움재로 사용할 경우 횡토압을 감소시키기 때문에 옹벽이나 교대의 뒷채움재료로 사용하기도 한다. 이와 같이 그 사용이 꾸준히 증가하고 있지만 뒷채움이나 연악지반상에 사용할 때 지오폼의 거동을 예측하는 적절한 수치모델이 아직은 개발되자 않았다. 본 연구에서는 지오폼의 응력-변형 특성을 연구하고 그 탄소성 예측모델을 제시하였다. 이를 위하여 삼축압축시험을 실시하였으며 구속응력과 지오폼의 밀도를 다양하게 변화시켜 그 응력-변형특성을 조사하고 회귀분석을 통하여 비선형 구성모델을 제시하였다. 그 결과 지오폼은 탄성 선형모델보다 탄소성모델 특성에 더 가까운 것을 알 수 있었으며 체적변화율과 축방향 변형률에는 특별한 상관 관계가 있음을 알 수 있었다.

  • PDF

An Analytical Study of Flexible Pavement Design Using Resilient Modulus Model of Expanded Polystyrene (EPS) (EPS 회복탄성계수 모델을 이용한 연성포장설계의 해석적 연구)

  • Park, Ki-Chul;Chang, Yong-Chai
    • Journal of the Korean Geosynthetics Society
    • /
    • v.14 no.2
    • /
    • pp.35-44
    • /
    • 2015
  • The resilient modulus model of EPS geofoam to be used for a flexible pavement design was developed. In this study, the model was applied to design the flexible pavement and to predict the magnitude of the deformation of EPS geofoam blocks as a subgrade in the flexible pavement structure by using the resilient modulus model of EPS geofoam (RMEG) program. The RMEG program presented how much the EPS geofoam subgrade settled over the designed duration and the AASHTO flexible pavement design equation with the resilient modulus of EPS geofoam noted that how long the flexible pavement endured under traffic loads with 70% reliability for the estimated duration with less than 5mm vertical deformation during 20.6 years without the significant pavement distress as a substitute material for the natural soils.

The Introduction of Egg-Cam Clay Model and Elasto-Plastic Analysis of Reinforcement Effect on Buried Pipe (Egg-Cam Clay 모델 제안 및 지중매설관의 보강효과의 탄소성모델 해석)

  • Ahn, Tae-Bong;Cho, Sam-Duck;Kim, Jin-Man
    • Journal of the Korean GEO-environmental Society
    • /
    • v.3 no.2
    • /
    • pp.5-14
    • /
    • 2002
  • In this study, stress-deformation characteristics of buried pipe are studied. A numerical model, i.e., Egg-Cam Clay is introduced for the analysis of soft clay. Cam Clay model has a difficulty in analyzing soft clay that has two properties of shrinkage and swelling. Egg-Cam Clay model is modified format of Cam Clay model. In addition, Mohr-Coulomb model using finite element method is employed to verify effects of the geogrid, EPS geofoam. Stress deformation of several cases of pipe and other reinforcemnt material combinations are analyzed. Geofoam and geogrid have positive effects on the deformation characteristics.

  • PDF

A Feasibility Study on Resilient Modulus of Expanded Polystyrene (EPS) Geofoam as a Flexible Pavement Subgrade Material (연성포장의 노반재료로서 EPS 지오폼의 회복탄성계수에 관한 적합성 연구)

  • Park, Ki-Chul;Chang, Yong-Chai
    • Journal of the Korean GEO-environmental Society
    • /
    • v.12 no.12
    • /
    • pp.63-70
    • /
    • 2011
  • Expanded Polystyrene (EPS) is a type of geosynthetic material manufactured with various strengths, unit weights, and dimensions. Due to recent advances in research on EPS, the use of EPS has increased dramatically. This super light weight material has a unit weight of approximately $0.16{\sim}0.47kN/m^3$, equivalent to 6.3~15.7 of that of most natural soils with conditions of fill materials. In spite of this advantage, it is noted that no standard method of resilient modulus test on EPS geofoam was reported and no literature on resilient modulus test methods for EPS geofoam exist. The main object of this study was to investigate feasibility of the resilient modulus of EPS when it was applied for flexible pavement. The investigation of the feasibility was completed based on the results from triaxial tests.

Analysis of Time-Dependent Deformation of Expanded Polystyrene (EPS) Geofoam as a Flexible Pavement Subgrade Material (연성포장의 노반재료로써의 EPS 지오폼의 시간의존적 변형 분석)

  • Park, Ki-Chul;Ramaraj, Babu;Chang, Yong-Chai
    • Journal of the Korean Geosynthetics Society
    • /
    • v.9 no.3
    • /
    • pp.57-65
    • /
    • 2010
  • The main objective of this study is to investigate the time-dependent deformation of EPS blocks under repeated loading conditions which is the one of the flexible pavement structure. The study comprised of both the experimental work and analytical modeling in order to understand the behavior of EPS blocks under repeated loading. The analytical modeling included the selection of a suitable model for describing the deformation behavior observed under repeated loading conditions, investigating the relationship among the unit weight, deformation and applied stress, analyzing the effect of repeated load on deformation. The test results were compared with the Findley's theory and model analysis with the results of this research under repeated loading conditions. Both Modified Findley's model and the proposed model can be adopted to illustrate the deformation behavior of EPS blocks under repeated loads.

  • PDF