• Title/Summary/Keyword: 지반계수

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Evaluation of Shear Elastic Modulus by Changing Injection Ratio of Grout (그라우트 주입률 변화에 따른 전단탄성계수 평가)

  • Baek, Seungcheol;Lee, Jundae;Ahn, Kwangkuk
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.2
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    • pp.51-55
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    • 2013
  • Among various construction methods, deep soil stabilization by chemical method have been widely used in order to improve soft ground. Dynamic variables using ground(such as sand, weathered granite soil and rock) -structure interaction design affected by dynamic load and cyclic load were studied a lot. However, there is something yet to learn about earthquake resistant design regarding reinforced ground by grout. Therefore, in this study using RC test, the correlation between shear strain and shear modulus with change of water content and injection rate in normal portland cement and clay was compared and analyzed by using Ramberg-Osgood model normalization As the result, dynamic coefficient was considerably affected by water content and grout injection rate.

Stress Distribution of Concrete Pavements under Multi-Axle Vehicle Loads Applied at Pavement Edges (모서리부 차량 다축하중에 의한 콘크리트 도로 포장의 응력 분포 특성)

  • Kim, Seong-Min;Cho, Byoung-Hooi;Lee, Sang-Hoon
    • International Journal of Highway Engineering
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    • v.8 no.4 s.30
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    • pp.13-24
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    • 2006
  • The stresses in concrete pavement systems are larger when vehicle loads are applied at pavement edges, and these large stresses significantly affect the behavior and performance of pavements. Therefore, in this study, the stress distribution and the critical stresses in concrete pavements were investigated using a finite element model when dual-wheel single-, tandem-, and tridem-axle loads were applied at pavement edges. First, the stress distribution along the longitudinal and transverse directions was analyzed, and then the effects of slab thickness, concrete elastic modulus, and foundation stiffness on the stress distribution were investigated. The effect of the tire contact pressure related to the tire print area was also studied. The location of the critical stress occurrence in concrete pavements was finally investigated. From this study, it was found that the critical concrete stress due to edge loads became larger as the concrete elastic modulus increased, the slab thickness increased, and the foundation stiffness decreased. The effect of the tire contact pressure on the critical stress was clear as the slab thickness became smaller. The critical stress location in the transverse direction was independent of the concrete elastic modulus and the foundation stiffness; however, it moved into the interior as the slab thickness increased. The critical stress location in the longitudinal direction was under the axle for single- and tandem-axle loads, but for tridem-axle loads, it tended to move under the middle axle from the outer axles as the concrete elastic modulus and/or slab thickness increased and the foundation stiffness decreased.

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A Study on the p-y Curves by Small-Scale Model Tests (모형실험을 통한 말뚝의 p-y 곡선에 관한 연구)

  • Kim, Tae-Sik;Jeong, Sang-Seom;Kim, Young-Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.1C
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    • pp.41-51
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    • 2008
  • The load distribution and deformation of single piles which is embedded in Jumunjin sand and Kimhae clay are investigated, based on small scale model tests. Special attention is given to the consideration of flexural rigidity in laterally loaded piles. To consider the flexural rigidity of the pile, tests are performed with the aluminium piles of three different length under different relative densities and undrained shear strength. The test results indicate that the initial slope from the results of tests is proportional to the depth and pile-soil rigidity in both soils. But the increasing rate of the initial slope in the clay is less than in the sand. In addition, the soil resistance is more related to the depth and soil condition than the pile rigidity. Base on the test results, an empirical formula is proposed, which is good agreement with previously published small scale model test and field lateral load test.

Identification of the Hualien Soil-Structure Interaction System Using Earthquake Response Data (지진계측자료를 사용한 화련 지반-구조물 상화작용계의 미지계수 추정)

  • 최준성
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.04a
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    • pp.249-258
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    • 2000
  • 본 논문에서는 지반-구조물 상호작용계의 강성에 관련된 물성값들을 지진계측결과를 바탕으로 효과적으로 추정할 수 있는 방법에 대해 연구하였으며 제안된 방법의 검증은 국제공동 연구의 일환으로 최근 대만의 화련에 건설된 대형지진시험구조물에서 계측된 지진 응답을 사용하여 수행하였다. 지반-구조물 상호작용계의 지진응답해석을 위해서 구조물과 근역지반은 축대칭유한요소로 모형화하고 원역지반은 축대칭 무한요소를 사용하였으며 이때 입력 지진하중은 부구조법에 근거한 파입력기법이 고려되었다 지진계측결과를 사용하여 각 영역의 물성값을 제약적 최속강하법을 사용하여 추정하였는데 추정된 계수들을 사용하여 계산된 지진응답이 계측치와 매우 잘 일치하여 추정결과의 타당성을 검증할 수 있었다.

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Input and System Identification of the Hualien Soil-Structure Interaction System Using Earthquake Response Data (지진응답자료를 사용한 화련 지반-구조물 상호작용계의 지진입력운동과 지반계수의 추정)

  • 최준성
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.04a
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    • pp.128-135
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    • 2001
  • 본 논문에서는 지반-구조물 상호작용계의 입력하중과 강성에 관련된 물성값들을 구조물에서 계측된 지진응답만을 사용하여 효과적으로 추정할 수 있는 새로운 방법을 제안하였는데, 제안된 방법은 비지계수 추정을 위한 목적함수가 입력하중에 독립적이기 때문에 구조물에서 계측된 지진응답만으로 미지계수의 추정이 가능하도록 되어있다. 본 연구에서 제안된 방법의 검증은 국제공동 연구의 일환으로 최근 대만의 화련에 건설된 대형지진시험 구조물에서 계측된 지진 응답을 사용하여 수행하였다. 추정된 입력하중과 지반과 구조물의 강성에 관련된 물성값들을 사용하여 계산된 지진응답의 계측치와 매우 잘 일치하여, 추정결과의 타당성을 검증할 수 있었다.

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Free Vibration Analysis of Thick Plates on Inhomogeneous Pasternak Foundation (비균질 Pasternak지반 위에 놓여진 후판의 자유진동해석)

  • 김일중;오숙경;이효진;이용수
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.852-857
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    • 2003
  • This paper has the object of investigating natural frequencies of thick plates on inhomogeneous Pasternak foundation by means of finite element method and providing kinematic design data lot mat of building structures. This analysis was applied for design of substructure on elastic foundation. Mat of building structure may be consisdered as a thick plate on elastic foundation. Recently, as size of building structure becomes larger, mat area of building structure also tend to become target and building structure is supported on inhomogeneous foundation. In this paper, vibration analysis or rectangular thick plate is done by use or serendipity finite element with 8 nodes by considering shearing strain of plate. The solutions of this paper are compared with existing solutions and finite element solutions with 4${\times}$4 meshes of this analysis are shown the error of maximum 0.083% about the existing solutions. It is shown that natrural frequencies depend on not only Winkler foundation parameter but also shear foundation parameter.

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Dynamic Friction Behavior of Interfaces Between Dense Dry Granular Soils and Construction Material(Concrete) (조밀한 건조조립토와 건설재료(콘크리트) 사이의 동마찰계수)

  • 김대상
    • Journal of the Korean Geotechnical Society
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    • v.17 no.6
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    • pp.207-213
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    • 2001
  • Shaking table tests to investigate the dynamic friction behavior of interfaces between dense dry granular soils and construction material(concrete) were performed and the results are reported. The results show the variation of dynamic interface friction coefficients between dense dry granular soils and construction material was small in the sliding velocity range employed in this study. It was also observed that dynamic interface friction coefficients decreased as mean grain sizes of granular soils increased. These coefficients were compared with the friction coefficients obtained from the peak internal friction angles of the same granular soils by plane strain compression tests.

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