• Title/Summary/Keyword: Reinforced Earth

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Vibration Transfer Characteristics of the Reinforced Soil SRWs Under the Simulated Cyclic Train Loading (모사열차 반복하중 재하시 블록식 보강토 옹벽의 진동전달특성)

  • 고태훈;이진욱;이성혁;황선근;김정무
    • Proceedings of the KSR Conference
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    • 2002.10a
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    • pp.626-632
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    • 2002
  • Geogrid is widely used as the reinforcement materials in railway earth structures in order to achieve efficient land utilization as well as securing safety in railway service lines in other countries. In this study, the real scale test was carried out to investigate the application of geogrid reinforced soil segmental retaining walls(SRWs) in railway. For this goal, the vibration transfer characteristics of reinforced soil segmental retaining walls was evaluated. The resonant frequencies of SRWs, vertical ground vibration in backfill and vertical/horizontal vibration at segmental units were acquired. This experimental data and analysis result can contribute to understand the vibration response behavior of SRWs.

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Comparative investigation on fatigue and moisture absorption behavior of hemp and Jute fibre polymer composites

  • Kumar, B. Ravi;Hariharan, S.S.
    • Structural Engineering and Mechanics
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    • v.81 no.6
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    • pp.729-736
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    • 2022
  • Earth is facing a serious problem of pollution and scarcity of energy sources. The synthetic fibers used in automobile and Aerospace manufacturing sectors are non-renewable and harmful to environment. International Agency such as FAA and SAE is forcing for green fuel, green materials and structures. Further exploration is much needed to understand its potential in structural applications. In the current study, hemp and Jute fibre based composites were developed and tested for assessing their suitability for possible applications in automobile and aerospace sectors. Composites were undergone tensile test, water absorption test, and fatigue analysis to understand its behavior under various loading conditions. The finite element analysis has been carried out to understand the fatigue behaviour of composites. The results revealed that the usage of hemp and jute fibre reinforced composites can improve mechanical properties and have shown a viable alternative to replace synthetic fibres such as glass fibres for specific applications. Hemp reinforced bio-composites have shown better performance as compared to Jute reinforced bio-composites while water resistance characteristics for hemp is poorer to jute fibres.

Evaluation of the Structural Stability of Rammed Earth Construction :The Case Restoration Project of the Stone Pagoda at Mireuksa Temple Site in Iksan

  • Min, Hwang-Sik;Choen, Deuk-Youm
    • Architectural research
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    • v.20 no.3
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    • pp.65-73
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    • 2018
  • The restoration of foundations supporting the immense load of the stone pagoda at Mireuksa Temple Site prioritizes securing its structural stability. But so far, rammed earth construction is still not easy to determine the structural stability. This paper aims to emphasize that a scientific experimental study was conducted on a rammed earth construction, to identify its methodology and obtain objective data about structural stability of the foundation work. An experimental study fabricated specimens from the soil that had been removed during the excavation survey, determined the allowable bearing capacity through plate load tests, and compared the results with the predicted stress after reassembly of the stone pagoda to estimate the structural stability. Then, the repair method was selected based on the experimental study result. The evaluation method of the restoration of foundations consisted of an examination of the allowable bearing capacity and settlement. The allowable bearing of the reinforced foundation was more than twice the contact pressure under the stacked stones of the pagoda. The possibility of settlement of the rammed earth foundation soil layer during the pagoda assembly is expected to be very low because the settlement amount of the reformed soil layer is less than half of the settlement of the stabilized existing soil layer.

Numerical Analysis on the Behavior of a Colluvium Slope Reinforced with Soil Nails and Anchors (소일네일과 앵커로 보강된 붕적층 비탈면의 거동에 관한 수치해석)

  • Jang, Myoung-Hwan;Kim, Hoon-Tae;Yoo, Nam-Jae
    • Journal of Industrial Technology
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    • v.33 no.A
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    • pp.73-80
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    • 2013
  • This paper is results of numerical analysis on the behavior of colluvium slope with combinations of soil nails and earth anchors during excavation. In order to maintain the stability of the colluvium cut, being composed of gravel and boulder and thus local in stability being expected during slope cut, temporary reinforcing method of soil nailing with shotcrete might be used. Subsequent method of cast-in-place facing with earth anchors can be used to maintain cut slope stable permanently. For the cut slope where these methods had been applied, the numerical techniques were applied to their behaviors and investigate the stability of the slope. Limit equilibrium methods were used to confirm to maintain the slope stability during and after excavation and application of those reinforcing methods. Another numerical technique of FEM was also used to find the stress and strain as well as deformation distribution in reinforcing materials and slope ground during excavation.

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A Planting Study on the Development of Eco-friendly Reinforced Earth-Retaining Wall Using Planting Green Net (환경친화형 그린넷 보강토 옹벽 개발을 위한 식생시험 연구)

  • Chung, Dae-Seouk
    • Journal of Environmental Science International
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    • v.16 no.9
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    • pp.1099-1102
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    • 2007
  • This paper presents eco-friendly planting method to overcome the problems of existing concrete retaining wall and gabion retaining wall, respectively, based on the examination on existing concrete and gabion retaining wall. Prior to doing this, proper design method was provided through pull out test. Planting method using gabion metal net and L shape green net retaining wall were compared and analyzed. According to this study, it is confirmed that reduction of construction period and economical profit in construction can be achieved by both manufacturing at the factory and self procurement at the job site as well as the use of metal net, which is applied as a substitution of existing strengthening material. For the effect of planting method, the use of L shape green net retaining wall shows superiority to environment-friendly gabion retaining wall in its ability to rootage and germination of the grass. The L shape green net retaining wall had excellent performance in helping rootage of grass and prevention of soil leakage, and even if raining period, remarkable damage of planting mat does not occur when planting mat is applied.

Behavior Analysis of Block Type Wall Constructed for Maintaining the Slope Stability of Rural Structure (농촌건축물 사면 안정성 확보를 위한 블록식 옹벽의 거동분석)

  • Shin, Bangwoong;Oh, Sewook;Kwon, Youngcheul
    • Journal of the Korean Institute of Rural Architecture
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    • v.2 no.2
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    • pp.115-126
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    • 2000
  • Retaining walls are used to prevent excessive movement of retained soils. Typical retaining walls include gravity, reinforced concrete, reinforced earth and tie-back. However, from a practical viewpoint there are still drawbacks among these often constructed retaining walls. New types of retaining walls constructed with precast concrete blocks are proposed. This type of retaining wall is incorporates each blocks interconnected with adjacent block by connecting unit to build up a flexible retaining-wall system. This paper focus to behavior characteristics includes deformation and distribution of lateral earth pressure by loading tests and FEM analysis. For model tests, a 1/10 scale reduce models are manufactured include unevenness part, drainage hole and connecting unit and steel wire used to connect each blocks with adjacent block. To simulate the real retaining walls closely, uneven parts are interconnected each other and the construction type of blocks and wall front inclination are varied to investigate the relative displacement of individual block and the location of maximum deformation of wall as increasing surcharging. Additionally, PENTAGON3D, which solve the geotechnical and other problem, used for verifying and comparing with model tests.

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Centrifuge Model Experiments on Behavior of Reinforced Earth Retaining Walls A Study due to Variation of Reinforcements (보강토 옹벽의 거동에 대한 원심모형실험 -보강재 변화에 의한 연구)

  • Heo, Yol;Ahn, Sang-Ro;Lee, Cheo-Keun
    • Geotechnical Engineering
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    • v.9 no.4
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    • pp.45-54
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    • 1993
  • In this paper, the behaviors of reinforced earth retaining walls according to material properties of reinforcement were performed through the centrifuge model tests. Skin element was used flexible aluminum plate in the process of tests. And reinforcements were used with aluminum foil strips and non -woven polyester sheets. As a result of it, model retaining wall utilizing non-woven polyester sheets than aluminum foil strips was supported at high stress level, and maximum horizontal displacement value of skin element was 0.6H height at model walls. In the other hand, coefficient relation diagram for evaluation of horizontal displacement according to skin element location was proposed using test results.

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Real-scale Accelerated Testing to Evaluate Long-term Performance for Bridge/Earthwork Transition Structure Reinforced by Geosynthetics and Cement Treated Materials (토목섬유와 시멘트처리채움재로 보강한 교량/토공 접속구조의 장기공용성 평가를 위한 실물가속시험)

  • Lee, Il-Wha;Choi, Won-Il;Cho, Kook-Hwan;Lee, Kang-Myung;Min, Kyung-Chan
    • Journal of the Korean Society for Railway
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    • v.17 no.4
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    • pp.251-259
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    • 2014
  • The transition zone between an earthwork and a bridge effect to the vehicle's running stability because support stiffness of the roadbed is suddenly changed. The design criteria for the transition structure on ballast track were not particular in the past. However with the introduction of concrete track is introduced, it requires there is a higher performance level required because of maintenance and running stability. In this present paper, a transition structure reinforced with geosynthetics is suggested to improve the performance of existing bridge-earthwork transition structures. The suggested transition structure, in which there is reinforcing of the approach block using high-tension geosynthetics, has a structure similar to that of earth reinforced abutments. The utilized backfill materials are cement treated soil and gravel. These materials are used to reduce water intrusion into the approach block and to increase the recycling of surplus earth materials. An experiment was performed under the same conditions in order to allow a comparison of this new structure with the existing transition structure. Evaluation items are elastic displacement, cumulative settlement, and earth pressure. As for the results of the real-scale accelerated testing, the suggested transition structure has excellent performance for the reduction of earth pressure and settlement. Above all, it has high resistance the variation of the water content.

Behavior of Geosynthetic Reinforced Modular Block Walls under Sustained Loading using Reduced-Scale Model Test (축소모형실험에 의한 지속하중하에서의 보강토 옹벽의 거동특성 연구)

  • Yoo, Chung-Sik;Kim, Sun-Bin;Byun, Joseph;Kim, Young-Hoon;Han, Dae-Hui
    • Journal of the Korean Geosynthetics Society
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    • v.5 no.1
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    • pp.1-7
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    • 2006
  • Despite a number of advantages of reinforced earth walls over conventional concrete retaining walls, there exit concerns over long-term residual deformation when used as part of permanent structures. In view of these concerns, time-dependant deformation characteristics of geosynthetic reinforced modular block walls under sustained loads were investigated using reduced-scale model tests. The results indicated that a sustained load can yield appreciable magnitude of residual deformation, and that the magnitude of residual deformation depends on the loading characteristic as well as reinforcement stiffness.

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