• Title/Summary/Keyword: Retaining Structure

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The Development and Application of KOESWall System (분리형 보강토 옹벽의 개발 및 적용사례)

  • 김영윤
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.10a
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    • pp.323-328
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    • 2001
  • In the ordinary reinforced earth wall, which was constructed by incremental construction method, the horizontal deformation of the facing due to the compaction induced horizontal earth pressure was unavoidable. Thus the KOESWall system which are adopted the isolated construction method was developed by I&S Eng. Co., Ltd. in 1999. Due to its systematical feature, KOESWall system is able to minimizes the horizontal deformation of reinforced wall effectively and it can be used as temporary structures more economically without the lacing block. In this report, it is shown that the concept and case histories of KOESWall system as a retaining structures.

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New Developments in Power Reactor Core Design

  • Johnson, R.D.
    • Nuclear Engineering and Technology
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    • v.4 no.2
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    • pp.137-150
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    • 1972
  • Three recently introduced tenchniques in the area of nuclear analysis are discussed : the structure-factor method of evaluating group material properties, the vector-synthesis method of generating three-dimensional multigroup flux distributions, and an indirect method of defining optimal restricted partitions of neutron phase-space. Each new method is compared with other commonly employed techniques and is shown to be a simplification which leads to a reductions in computational effort while retaining acceptable accuracy.

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A Study on the Failure Behavior of the Reinforced Earth Wall Structures according to the Deformed Types of the Face (전면부 변형형태에 따른 보강토 벽체 구조물의 파괴거동에 관한 연구)

  • 김준석;이상덕
    • Journal of the Korean Geotechnical Society
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    • v.15 no.4
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    • pp.167-173
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    • 1999
  • In this paper the failure behavior of the reinforced earth retaining wall structures according to the deformed types of the face was studied by model test using carbon rods. In model test the behavior of the face for the model of the reinforced earth wall was divided into three cases : the displacement of the top part(case 1), the lateral displacement(case 2) and the displacement of the lower part (case 3). The photographic method was applied to examine the failure line of the deformed wall with the naked eye. The failure line shows a parabolic shape for case 1, a large circular arc for case 2 and a logarithmic spiral for case 3 in the experimental results. The design failure line for the coherent gravity structure hypothesis was most similar to the failure line for the case of the lower part displacement.

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The Behavior of Earth Retaining Structures Using p-y Curve with Coupling (p-y 특성곡선의 Coupling을 고려한 토류벽의 거동해석)

  • Kim, Soo Il;Jeong, Sang Seom;Chang, Buhm Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.3
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    • pp.553-563
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    • 1994
  • The behavior of earth retaining structure was investigated by considering coupling between soil springs in elasto-plastic soil. For the computation of soil reaction, soil on both sides of walls was simplified as e1asto-plastic springs, and the required horizontal displacement to mobilize Terzaghi's active and passive state was applied to construct the p-y curve. Reliability on computer program developed is verified through the comparison between prediction and in-situ measurements. Based on the results obtained, it is found that the prediction by using coupling between soil springs simulates well the general trend observed by the in-situ measurements. It is also found that the horizontal displacement required for the active state gives a very small effect to the displacement of walls in the sandy soil.

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Improved Effects of Reinforced Wall with Types of Connection Methods (보강재 연결 유.무에 따른 보강토옹벽의 보강효과)

  • 신은철;최찬용
    • Geotechnical Engineering
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    • v.14 no.5
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    • pp.67-76
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    • 1998
  • The commonly used method to secure the stability of reinforced retaining structure is the reinfocement of backfill with connection attached or unattached to the geogrid type wall. Laboratory model tests for both cartes were conducted to investigate the effectiveness of geogridreinforcement, length of reinforcement inclusion, failure envelop, and the relationships between the face wall displacement and vertical settlement. The bearing capacity of each case was also determined. According to the model test results, geogrid-reinforced rigid wall is very effective for increasing the bearing capacity and reducing the displacement of retaining wall. The observed sliding line of model test is similar to the theoretical one.

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Optimizing Laser Scanner Selection and Installation through 3D Simulation-Based Planning - Focusing on Displacement Measurements of Retaining Wall Structures in Small-scale Buildings -

  • Lee, Gil-yong;Kim, Jun-Sang;Yoou, Geon hee;Kim, Young Suk
    • Korean Journal of Construction Engineering and Management
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    • v.25 no.3
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    • pp.68-82
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    • 2024
  • The planning stage of laser scanning is crucial for acquiring high-quality 3D source data. It involves assessing the target space's environment and formulating an effective measurement strategy. However, existing practices often overlook on-site conditions, with decisions on scanner deployment and scanning locations relying heavily on the operators' experience. This approach has resulted in frequent modifications to scanning locations and diminished 3D data quality. Previous research has explored the selection of optimal scanner locations and conducted preliminary reviews through simulation, but these methods have significant drawbacks. They fail to consider scanner inaccuracies, do not support the use of multiple scanners, rely on less accurate 2D drawings, and require specialized knowledge in 3D modeling and programming. This study introduces an optimization technique for laser scanning planning using 3D simulation to address these issues. By evaluating the accuracy of scan data from various laser scanners and their positioning for scanning a retaining wall structure in a small-scale building, this method aids in refining the laser scanning plan. It enhances the decision-making process for end-users by ensuring data quality and reducing the need for plan adjustments during the planning phase.

Seismic performance evaluation of agricultural reservoir embankment based on overtopping prevention structures installation

  • Bo Ra Yun;Jung Hyun Ryu;Ji Sang Han;Dal Won Lee
    • Korean Journal of Agricultural Science
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    • v.50 no.3
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    • pp.469-484
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    • 2023
  • In this study, three types of structures-stepped gabion retaining walls, vertical gabion retaining walls, and parapets-were installed on the dam floor crest to prevent the overflow of deteriorative homogeneous reservoirs. The acceleration response, displacement behavior, and pore water pressure ratio behavior were compared and evaluated using shaking-table model tests. The experimental conditions were set to 0.154 g in consideration of the domestic standard and the seismic acceleration range according to the magnitude of the earthquake, and the input waveform was applied with Pohang, Gongen, and artificial earthquake waves. The acceleration response according to the design ground acceleration increased as the height of the embankment increased, and the observed value were larger in the range of 1.1 to 2.1 times the input acceleration for all structures. The horizontal and vertical displacements exhibited maximum values on the upstream slope, and the embankment was evaluated as stable and included within the allowable range for all waveforms. The settlement ratio considering the similarity law exhibited the least change in the case of the parapet structure. The amplification ratio was 1.1 to 1.5 times in all structures, with the largest observed in the dam crest. The maximum excess pore water pressure ratio was in the range of 0.010 - 0.021, and the liquefaction evaluation standard was within 1.0, which was considered very stable.

A Case Study of Hybrid Reinforced Geo-Structure using Reinforced Concrete Block and Slope (콘크리트 블록식 보강토 옹벽과 보강사면을 복합으로 이용한 보강토의 설계 및 시공사례 연구)

  • Kim, Young-Nam;Chae, Young-Su;Lee, Kang-Il
    • Journal of the Korean Geosynthetics Society
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    • v.4 no.4
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    • pp.47-56
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    • 2005
  • With the need of efficient site use retaining walls have frequently used. Of them dry cast modular block wall(MBW), in which geogrid and concrete block are used is getting popular because of its simplicity and economical efficiency of construction. However, since this method is based on the theory of earth pressure, sands with good quality should be used. In contrast, reinforced soil slope(RSS) that the slope is less than $70^{\circ}$ can use wider range of soil than MBW. A hybrid reinforced geo-structure might be a good alternative in view of overcoming difficulty obtaining soils with good quality as well as maximizing the efficiency of site use. This method is composed of reinforced block wall and reinforced soil slope. In this method, reinforced block wall is constructed up to a certain height vertically at ground boundary first. Reinforced soil slope is then constructed on the block wall subsequently. This paper introduces several technical points that should be taken into account in design and construction.

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Maintenance Characteristics of Geotechnical Structures in Cold Region for Freeze Damage Analysis (동결피해분석을 위한 저온지역 지반구조물의 보수보강특성)

  • Hwang, Youngcheol
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.3
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    • pp.35-40
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    • 2013
  • In most cases, Geotechnical Structures installed in freezing areas require extra countermeasures for reducing freeze damage. However, in terms of domestic tunnels, studies and case reports for geotechnical structures such as tunnels and retaining walls are not fluently carried out, causing lack of research about ways to decrease freeze damage. For these causes, domestic design criteria about structures does not specifically institutionalization for geotechnical structures. This research have done on-site investigation about tunnels, cut slopes and retaining walls. Also, this research includes the process of analyzing the histories of maintenance for class 1 and class 2 structures that happened in the past 40 years, studying characteristics of structure's maintenance and reinforcement in different areas with different climate. As the result, it was analyzed that domestic geotechnical structures showed need for longer maintenance and reinforcement that are located in Gangwon mountain area, Gangwon north region and Gyeonggi north region where the temperature is relatively low. This research can be concluded in need for revision of design criteria for structures located in freeze damage area.

Electroosmotic Water Removal in Wet Porous Materials (다공성 흡수매체에 대한 정전삼투 탈수효과)

  • Park, Seon-Mi;Park, Mi-Jung;Ha, Ji-Soo;Chang, Hyuk-Sang
    • Clean Technology
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    • v.16 no.2
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    • pp.145-152
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    • 2010
  • Various technical methods are applied for removing water from the water-retaining media, and the energy efficiency is the main concern in those methods. The electroosmotic process is studied as an efficient way for dewatering. An experimental electroosmotic reactor is designed and used for evaluating the effects of operational variables. The operational variables such as the electrical fields and the structure of water-retaining medias were studied. Three different shapes of polarized electric fields in ranges of 0-100 V/cm and 0-10 kHz are used as the source of electric voltage. The effect of electroosmotic process with respect to the structural variation is estimated by filling the electroosmotic reactor with the glass beads in 0.18 mm, 0.35 mm and 1.2 mm in diameters. 6% of water removal is obtained in the simulating electroosmotic reactor of glass beads. The estimated energy consumption in the simulating electroosmotic was 330~490 cal/g-water.