• Title/Summary/Keyword: Reinforced earth

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Time-Dependent Deformation Characteristics of Geosynthetic-Reinforced Soil Using Plane Strain Compression Tests (평면변형압축시험을 이용한 보강토의 시간 의존적 변형 특성 연구)

  • Yoo Chung-Sik;Kim Sun-Bin;Lee Bong-Won
    • Journal of the Korean Geotechnical Society
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    • v.21 no.10
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    • pp.85-97
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    • 2005
  • Despite a number of advantages of reinforced earth walls over conventional concrete retaining walls, there exist concerns over long-term residual deformation when subjected to repeated and/or cyclic loads, especially when used as part of permanent structures. In view of these concerns, in this paper time-dependent deformation characteristics of geosynthetic reinforced soil under sustained and/or repeated loads were investigated using a series of plane strain compression tests on geogrid reinforced weathered granite soil specimens. The results indicate that sustained or repeated loads can yield appreciable magnitudes of residual deformations, and that the residual deformations are influenced not only by the loading characteristics but by the mechanical properties of geogrid. It is also found that the preloading technique can be effectively used in controlling residual deformations of reinforced soils subjected to sustained and/or repeated loads.

A Case Study of Extra Reinforcement by Road Extension work on Existing Cut Slope Reinforced with Counterweight Fill and Stabilizing Piles (압성토 및 억지말뚝으로 보강된 도로의 확장공사로 인한 추가 보강사례 연구)

  • Park, Jeong-Yong;Kim, Woo-Seong;Kim, Jae-Kyoung;Yang, Tae-Sun;Na, Kyung-Joon
    • Journal of Korean Society of societal Security
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    • v.1 no.2
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    • pp.67-72
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    • 2008
  • To confirm the stability of a cut slope in the road extension construction site, several investigations were carried out and countermeasures of slope was studied. This paper describes a study of design case of extra reinforcement on existing cut slope reinforced by preloading and piles in roads. To investigate the effect of stabilizing piles installed in a cut slope, an instrumentation system also designed, was. As a result that the stabilizing file and earth anchor are considered as the extra reinforcement, both stabilizing pile and earth anchor guarantee the stability of cut slope. However, stabilizing pile is selected in aspects of economy and continuity to the existing cut slop reinforcement including counterweight fill and stabilizing piles.

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Shape Optimization for Reinforced Concrete Culvert (철근콘크리트 암거의 형상 최적화)

  • Kim, Kee-Dae
    • Journal of the Korean Society of Industry Convergence
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    • v.5 no.3
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    • pp.261-268
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    • 2002
  • In this paper, the shape optimization is considered over the upper slab of reinforced concrete culvert. The sequential linear programming method (SLP) is used as a rational approach to this shape optimization. To make a comparison between the arch shaped member and the straight member for the upper slab, the culverts with 5~20m earth height were adopted. It is shown that the optimum rise/span is about 7%-13%, and the arch shaped member is more cheap (over 10%) than the straight member for the construction cost.

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A Study on Architectural Features and Current Status of Earth Housing (흙주거의 건축적 특성 및 이용현황 분석)

  • Kim Jeong-Gyu;Jeong Joo-Seong
    • Journal of the Korean housing association
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    • v.17 no.1
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    • pp.97-105
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    • 2006
  • The purposes of this study are to find out the current status and features of earth housing, and to explore users' level of satisfaction and needs of improvement about earth housing. Primary findings are as follows: (1) The area of earth housing is generally 25-34 pyong and the construction cost of earth housing is usually 3,000,000-3,400,000 won per pyong. (2) The age of earth house users is generally forties, fifties, and sixties. And their occupation is usually retiree and farmer. The age of earth based pension users is generally twenties and thirties. (3) The construction method of earth housing is usually earth brick structure reinforced with wood structure and earth brick structure(adobe). (4) The finish of outer wall is generally earth brick laying and earth plaster. And the finish of inner wall is usually wall paper and earth plaster. Roof tile and asphalt shingle is frequently observed as roof finish. (5) Users' satisfaction about earth housing is investigated high level. Especially, the satisfaction degrees about faculty of humidity control, stink elimination, prevention from sick house syndrome, support for psychological stabilization and deep sleep are observed very highly. (6) Reduction of construction cost and prevention of crack is investigated as needs of improvement about earth housing.

The Comparative Experiment of Geogrid Reinforcement Types with Construction Stage on Segmental Retaining Walls (블록식 보강토 옹벽에서의 시공단계별 보강재 타입에 따른 거동비교)

  • Lee, Sung-Hyouk;Lee, Jin-Wook;Choi, Chan-Yong
    • Journal of the Korean Geosynthetics Society
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    • v.11 no.4
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    • pp.1-8
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    • 2012
  • In this study, the earth pressure, displacement and strain were compared with reinforcement types at segmental retaining wall through full scale model test. The test results found that the measurement of earth pressure and displacement at wall for the fully reinforced retaining wall are different from those for the partly reinforced retaining wall. The analyses of these results would suggest that the used of geoogrid allowed the vertical earth pressure and displacement at wall to be reduced. The horizontal earth pressure in upper and lower part of wall can change with reinforcement type and earth deformation and were larger than the active and the rest pressure. Also, the lateral earth pressure and displacement of wall have a very high a correlation. It was found that the strain contour distribution of reinforcements was occurred a large strain at cental part of wall in segmental retaining wall system.

Comparison of earth pressure around pipe-roof between UPRS and front-jacking method (UPRS 공법과 프론트잭킹 공법의 파이프루프 주변 현장토압 계측결과 비교)

  • Sim, Youngjong;Jin, Kyu-Nam;Song, Ki-Il
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.5
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    • pp.513-522
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    • 2015
  • This study is to confirm the effect of pre-installed pipe-roof by measuring earth pressure acting on the underpass. In recently developed trenchless methods pre-inserted steel pipes before ground excavation to form pipe-roof are connected each other with re-bars and filled with mortar. In this study, focusing on the Upgraded Pipe Roof Structure method (UPRS) and Front-Jacking, earth pressure around pipe-roof is measured after insertion of steel pipe to ensure the effect of earth pressure reduction. In case of the UPRS earth pressure is considerably reduced because of the reinforced effect of pipe-roof. In case of the Front-Jacking in which the whole underpass structure is pushed into the ground, earth pressure is not reduced as expected, because the pre-installed pipes are not needed to be reinforced.

A Study on Connection Strength Evaluation of Wall Facing/Geogrid Using I-type Connection Device (I형 연결장치를 이용한 전면블록/지오그리드 보강재의 연결강도 평가)

  • Han, Jung-Geun;Hong, Ki-Kwon;Cho, Sam-Deok;Lee, Kwang-Wu
    • Journal of the Korean Geosynthetics Society
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    • v.8 no.3
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    • pp.45-52
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    • 2009
  • The use of geogrid-reinforced earth wall technologies has progressed rapidly over the past 10 years in Korea because these technologies have advantages such as economical efficiency, graceful appearance, and easy construction. The geogrid used in the reinforced earth wall with concrete block facing can be subjected to damage among the upper and lower blocks and at the interface between the block and the geogrid. Therefore, when design of the geogrid-reinforced soil walls the required connection strength of the geogrid to the wall facing is an issue. In this study, new connection system between facing block and geogrid is developed to improve the damages of geogrid in the existing connection systems. The new connection devices are made of steel and have I-shape. This paper describes the test method and results of the laboratory testing for determination of connection strength in connection system using the I-type connection device.

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Behavior Characteristics of Railway Roadbed Retained by Geosynthetic Reinforced Segmental Wall Under Train Load (열차 하중 작용 시 블록식 보강토 옹벽으로 지지된 철도 노반의 거동)

  • Lee, Seong Hyeok;Choi, Chan Yong;Lee, Jin Wook
    • Journal of the Korean Society for Railway
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    • v.15 no.5
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    • pp.467-475
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    • 2012
  • Static and dynamic train load tests were conducted to evaluate the train load transfer mechanism in the roadbed which was retained by two types (fully and partially) of segmental retaining walls reinforced by geogrid. The test roadbed was 2.6m high, 5m wide, and 6m long. A combination of earth pressure gages, displacement transducers, and strain gages were placed in specific locations to measure the responses. Test results showed that the wall displacement pattern as well as the earth pressure for the fully reinforced retaining wall was different from those for the partially reinforced retaining wall. In the dynamic train load test, the strain in the upper part of the wall tended to decrease, and both the residual deformation and the rate of the deformation were significantly lower than those in the current design standard.

Behavior of Failure on Agricultural Reservoirs Embankment by Riprap Reinforcement Method (Riprap으로 보강된 농업용 저수지 제체의 붕괴거동)

  • Lee, Dal Won;Noh, Jae Jin
    • Journal of The Korean Society of Agricultural Engineers
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    • v.56 no.6
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    • pp.63-73
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    • 2014
  • In this study, the large scale test was performed to investigate the behavior of failure on the embankment and spillway transitional zone by overtopping. The pore water pressure, earth pressure, settlement and failure behaviors according to several reinforcing method were compared and analyzed. The pore water pressure showed a small change in the spillway transition zone and core, indicating that the riprap and geotextile efficiently reinforced the embankment, but non-reinforcement showed a largely change in pore water pressure. The earth pressure by riprap and geotextile at upstream slope and bottom core increased rapidly with the infiltration of the pore water by overtopping. And the earth pressure at crest showed a smally change due to effect of the inclined core. A settlement by riprap showed a small change and the geotextile decreased a rapidly due to failure of crest. The width of failure by riprap at intermediate stage (50 min) showed a largely due to sliding of crest. But, the width and depth of the seepage erosion after the intermediate overtopping period (100 min) were very small due to the effect of riprap than geotextile and non-reinforcement which delayed failure. It has the effect that protect reservoir embankment from erosion in the central part. The pore water pressure at the spillway transition zone due to overtopping increased a rapidly in the case of non-reinforcement, but the reinforced methods by geotextile and riprap showed a smally change. Therefore, the reinforced method by riprap and geotextile was a very effective method to protect permanently and the emergency an embankment due to overtopping, respectively.