• Title/Summary/Keyword: 블록식 옹벽

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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.

Effect of Foundation Stiffness on Behavior of Soil-reinforced Segmental Retaining Walls (기초지반의 강성이 보강토 옹벽의 거동에 미치는 영향)

  • 유충식;김주석
    • Journal of the Korean Geotechnical Society
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    • v.18 no.4
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    • pp.7-19
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    • 2002
  • This paper presents the results of an investigation on the effect of foundation stiffness on the performance of soil-reinforced segmental retaining walls (SRWalls). Laboratory model tests were performed using a reduced-scale physical model to capture the fundamentals of the manner in which the foundation stiffness affects the behavior of SRWalls. A series of finite-element analyses were additionally performed on a prototype wall in order to supplement the findings from the model tests and to examine full-scale behavior of SRWalls encountered in the field. The results of the present investigation indicate that lateral wall displacements significantly increase with the decrease of the foundation stiffness. Also revealed is that the increase in wall displacements is likely to be caused by the rigid body movement of the reinforced soil mass with negligible internal deformation within the reinforced soil mass. The findings from this study support the current design approaches, in which the problem concerning the foundation condition are treated in the frame work of the external stability rather than the internal stability. The implications of the findings from this study to current design approaches are discussed in detail.

Design Case Study of Geosynthetic Reinforced Segmental Retaining Walls in Tiered Configuration (다단식 보강토 옹벽의 설계 사례 연구)

  • 유충식;허병주
    • Journal of the Korean Geotechnical Society
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    • v.19 no.6
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    • pp.115-125
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    • 2003
  • This paper presents the results of design case study on soil-reinforced segmental retaining walls in tiered configuration. Six different field walls were examined to investigate the appropriateness of their designs within the context of the current design guidelines based on limit equilibrium. Slope stability analysis against the compound failure mode, which is frequently ignored during design, was additionally performed based on the method recommended by FHWA design guidelines. The results indicate that the as-built designs of some of the walls examined do not meet the minimum factors of safety for the external and Internal stabilities, and for the compound failure mode. The implications of the findings from this study are discussed.

Behavior of Reinforced Earth Retaining Wall for Permitting Reinforcement to Subside with Monitoring (현장계측을 통한 보강재 침하형 보강토 옹벽의 거동특성)

  • Chung, Jin-Hyuck;Oh, Jong-Keun;Lee, Song
    • Journal of the Korean Geotechnical Society
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    • v.25 no.2
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    • pp.5-15
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    • 2009
  • The conventional reinforced earth retaining wall has the connector system to fix the reinforcement and block. However, this system defect may cause the crack of block and the rupture of reinforcement due to the stress concentration near the face of reinforced earth retaining wall. Hence, the new connector system which was able to allow the settlement of reinforcement was developed in this study and a test was carried out in the study area which is divided into the conventional reinforced earth retaining wall and reinforced Earth Retaining Wall driving the settlement. As the results of field monitoring in situ, the ratio of tensile force calculated at maximum value on contiguous portion of front block showed that the settlement type decreased the stress concentration near the face of front block greater than the conventional type.

Evaluation on Stability of Reinforced Earth Wall using Geosynthetic Strip with Rounded Band Anchor (띠형 섬유보강재가 적용된 블록식 보강토옹벽의 안정성 평가)

  • Lee, Kwang-Wu;Cho, Sam-Deok;Han, Jung-Geun;Hong, Ki-Kwon
    • Journal of the Korean Geosynthetics Society
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    • v.11 no.3
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    • pp.43-51
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    • 2012
  • This paper describes the stability evaluation of reinforced earth wall using geosynthetic strip based on field test. The wall facing, which is applied in field, is able to present excellent scenery, and the reinforcement has improvement effect of pullout resistance based on rounded band anchor. The measurement is conducted according to construction elapsed time of structure for earth pressure, horizontal displacement of wall facing and reinforcement strain in field test. The evaluation results show that the measured earth pressure is less than theoretical earth pressure due to dispersion effect of earth pressure by geosynthetic strip. The horizontal displacement of wall facing is also satisfied a empirical criteria. The measured strain of reinforcement had nearly no effect on stability of the reinforced earth wall. Therefore, the geosynthetic strip with rounded band anchor can be applied in the reinforced earth wall, and the reinforced earth wall with geosynthetic strip can be commonly used in field because it has a structural stability.

Effects of Facing Types and Construction Procedures on the Stability of Reinforced Earth Wall (전면벽 및 축조순서가 보강토옹벽의 안정성에 미치는 영향)

  • Lim Yu-Jin;Jung Jong-Hong;Park Young-Ho
    • Journal of the Korean Geotechnical Society
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    • v.20 no.7
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    • pp.119-126
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    • 2004
  • A small-scale reinforced earth wall was constructed in a laboratory to investigate the effect of wall rigidity and of construction sequence on the wall. A full continuous wall facing and a discrete wall facing were designed and constructed for tests. These two different facing systems should adapt different construction procedures due to their different facing shapes. The model wall was built with geo-grid reinforcement, sand, and facings on rigid surface. The model wall was instrumented with earth pressure gages, LVDTs, and strain gages. The experimental results have shown differences in wall behavior related to construction sequence and types of wall facing. It is found in this study that the reinforced earth wall built with full continuous facing is safer than the reinforced earth wall built with the discrete wall facing.

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.

A Study on Stability and Economic feasibility according to Height on the MSE Wall with Pacing Panel (고속도로 도로부에 시공된 패널식 보강토 옹벽의 높이별 안전율과 경제성 검토)

  • Park, Min-Cheol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.5
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    • pp.54-63
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    • 2018
  • In this study, the stability and economic feasibility of a MSE (Mechanically stability earth) wall with a pre-cast concrete pacing panel was investigated for a standard section of highway. Based on the design criteria, the MSE walls of the panel type were designed considering the load conditions of the highway, such as the dead load of the concrete pavement, traffic load, and impact load of the barrier. The length of the ribbed metal strip was arranged at 0.9H according to the height of the MSE walls. Because the length of the reinforcement was set to 0.9H according to the height of the MSE wall, the external stability governed by the shape of the reinforced soil was not affected by the height increase. The factor of safety (FOS) for the bearing capacity was decreased drastically due to the increase in self-weight according to the height of the MSE wall. As a result of examining the internal stability according to the cohesive gravity method, the FOS of pullout was increased and the FOS of fracture was decreased. As the height of the MSEW wall increases, the horizontal earth pressure acting as an active force and the vertical earth pressure acting as a resistance force are increased together, so that the FOS of the pullout is increased. Because the long-term allowable tensile force of the ribbed metal strip is constant, the FOS of the fracture is decreased by only an increase in the horizontal earth pressure according to the height. The panel type MSE wall was more economical than the block type at all heights. Compared to the concrete retaining wall, it has excellent economic efficiency at a height of 5.0 m or more.