• Title/Summary/Keyword: retaining wall

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A Study of the Optimal Displacement Analysis Algorithm for Retaining Wall Displacement Measurement System Based on 2D LiDAR Sensor (2D LiDAR 센서 기반 흙막이 벽체 변위 계측 시스템의 최적 변위 분석 알고리즘 연구)

  • Kim, Jun-Sang;Lee, Gil-yong;Yoou, Geon hee;Kim, Young Suk
    • Korean Journal of Construction Engineering and Management
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    • v.24 no.2
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    • pp.70-78
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    • 2023
  • Inclinometer has several problems of 1)difficulty installing inclinometer casing, 2) measuring 2D local lateral displacement of retaining wall, 3) measurement by manpower. To solve such problems, a 2D LiDAR sensor-based retaining wall displacement measurement system was developed in previous studies. The purpose of this study is to select a displacement analysis algorithm to be applied in the retaining wall displacement measurement system. As a result of the displacement analysis algorithm selection, the M3C2 (Multiple Model to Model Cloud Comparison) algorithm with a displacement estimation error of 2mm was selected as the displacement analysis algorithm. If the M3C2 algorithm is applied in the system and the reliability of the displacement analysis result is secured through several field experiments. Convenient management of the displacement for the retaining wall is possible in comparison with the current measurement management.

A Study on the Characteristics of Vascular Plants in the Stone Retaining Wall of Gudeuljang Paddy Fields in Cheongsan-Island (청산도 구들장논 석축(石築)의 관속식물 특성 연구)

  • Cha, Doo-Won;Kim, Ji-Yeon
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.41 no.1
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    • pp.1-9
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    • 2023
  • This study was carried out as basic data for the conservation and management of plant diversity in the Gudeuljang paddy fields stone retaining wall of Cheongsan-island by identifying the characteristics of vascular plants targeting Gudeuljang paddy fields stone retaining wall in Cheongsan-island. The total vascular plants of the Gudeuljang paddy fields stone retaining wall in Cheongsan-island have been identified with a total of 184 taxa of 60 families, 142 genera, 170 species, 5 subspecies, 9 varieties. Rare plants were 1 taxa, Korea endemic plants were 2 taxa, floristic regional indicator plants were 28 taxa, rock vegetation was 20 taxa, and invasive alien plants were 25 taxa. Among them, Selliguea hastata (Thunb.) Fraser-Jenk., a rare plants, has been identified as a small number of individuals in the Gudeuljang paddy fields stone retaining wall in Buheung-ri and Cheonggye-ri, but it is necessary to conservation the habitat because there is a concern that the species and population will decrease due to damage and neglect of the Gudeuljang paddy fields stone retaining wall.

Seismic lateral earth pressure analysis of retaining walls

  • Ismeik, Muhannad;Shaqour, Fathi
    • Geomechanics and Engineering
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    • v.8 no.4
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    • pp.523-540
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    • 2015
  • Based on limit equilibrium principles, this study presents a theoretical derivation of a new analytical formulation for estimating magnitude and lateral earth pressure distribution on a retaining wall subjected to seismic loads. The proposed solution accounts for failure wedge inclination, unit weight and friction angle of backfill soil, wall roughness, and horizontal and vertical seismic ground accelerations. The current analysis predicts a nonlinear lateral earth pressure variation along the wall with and without seismic loads. A parametric study is conducted to examine the influence of various parameters on lateral earth pressure distribution. Findings reveal that lateral earth pressure increases with the increase of horizontal ground acceleration while it decreases with the increase of vertical ground acceleration. Compared to classical theory, the position of resultant lateral earth force is located at a higher distance from wall base which in turn has a direct impact on wall stability and economy. A numerical example is presented to illustrate the computations of lateral earth pressure distribution based on the suggested analytical method.

Investigation on Behavior of Two-Level Soil-Reinforced Segmental Retaining Walls Using Finite Element Analysis (유한요소해석을 통한 계단식 보강토 옹벽의 거동특성)

  • 유충식;전영우
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.689-696
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    • 2002
  • The behavior of two-level soil-reinforced segmental retaining wall was examined using the finite element analysis. A number of different case was analyzed by varying the reinforcement length and the offset distance between the upper and lower wall. The results indicate that the interaction between the upper and lower walls can be neglected the upper wall is located beyond the distance of the lower wall height. A so found is that for moderate offset distances, the interaction between the two walls generally is limited to the external stability of the wall. Implication of the findings are discussed

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Analysis of Damage Cases of Reinforced Earth Retaining Walls for Expressways at the Time of Introduction 30 Years (도입 30년 시점에서 고속도로 보강토옹벽의 손상사례 분석)

  • Do, Jongnam;Kim, Nagyoung;Kim, Myoungil;Park, Doohee
    • Journal of the Korean GEO-environmental Society
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    • v.21 no.12
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    • pp.29-34
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    • 2020
  • Reinforced earth retaining walls were developed in France in the 1970s and began to be applied in earnest to Korea in the 1990s. And now, about 1,300 reinforced soil retaining walls support the embankment of highways and bridge connections. The reinforced earth retaining wall construction technology has evolved day by day, and in recent years the reinforced earth retaining wall itself has been developed and introduced as a demonstration. However, various damages are constantly occurring in the reinforced earth retaining walls constructed throughout the highway. The cause of this was analyzed as minor defects in the design, construction, and maintenance stages. The solution for this is a change in perception of the importance of each individual process, but this does not form overnight. In this study, 30 years have passed since the introduction of the reinforced soil retaining wall on the highway, the damage cases were analyzed and categorized that have occurred in the reinforced soil retaining wall so far, and attempted to present a confrontation. As a result, the damage occurring on the reinforced soil retaining wall was divided into 10 types, and the causes and countermeasures in the design, construction, and maintenance stages for each were derived.

A Study on the Selection Model of Retaining Wall Methods Using Support Vector Machines (Support Vector Machine을 이용한 흙막이공법 선정모델에 관한 연구)

  • Kim, Jae-Yeob;Park, U-Yeol
    • Korean Journal of Construction Engineering and Management
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    • v.7 no.2 s.30
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    • pp.118-126
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    • 2006
  • There is a greater importance for underground work designed and built in the urban areas when it comes to considering the cost-effectiveness and the period of construction commensurate with an increasing trend of skyscrapers. At this stage of underground work, it's extremely necessary to choose a proper earth retaining method. Therefore, the study has suggested the rational retaining wall method by developing the support vector machine(SVM) model as a tool to choose a proper retaining wall method applied at the stage of selecting the earth retaining method. In order to develop the SVM model, the binary SVM classifier is expanded into a multi-class classifier. and to present the feasibility of our SVM model, we considered 129 projects. Applying the 'SVM Model' developed in the study to the designing and developing stages of the earth retaining work will contribute to the successful outcomes by decreasing any changes of design from implementing the earth retaining.

A Study on the Selection Model of Retaining Wall Methods Using Case-Based Reasoning (사례기반추론을 이용한 흙막이공법 선정모델에 관한 연구)

  • Kim Jae-Yeob;Park U-Yeol;Kim Gwang-Hee;Kim Joong-Koo
    • Korean Journal of Construction Engineering and Management
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    • v.5 no.5 s.21
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    • pp.76-83
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    • 2004
  • There is a greater importance for underground work designed and built in the urban areas when it comes to considering the cost-effectiveness and the period of construction commensurate with an increasing trend of skyscrapers. At this stage of underground work, it's extremely necessary to choose a proper earth retaining method. However, a frequent change order during construction happens in Korea where different performers design and construct separately, so there is a great possibility for the change order to affect the aspects of construction cost and period which normally define the outcome of construction work. Therefore, the study has suggested the rational retaining wall method by developing the case-based reasoning model as stool to choose a proper retaining wall method applied at the stage of selecting the earth retaining method. Applying the 'CBR Model' developed in the study to the designing and developing stages of the earth retaining work will contribute to the successful outcomes by decreasing any changes of design from implementing the earth retaining work.

Application of Prefabricated Retaining Walls with Steel Lagging (강재 요소를 적용한 조립식 흙막이 벽체에 관한 연구)

  • Hong, Jong woo;Choi, Jae Soon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.6
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    • pp.1277-1285
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    • 2015
  • It has been known that the conventional retaining wall system with timber lagging and H pile has several problems such as the irregular gap between H-piles, cutting or adding to standard timber, back fill over first step excavation, and especially break-down accident at the disjoint of wall system. In the practical excavation, these problems may lead to worker's accident and the inefficiency of construction economy. To solve the above problems, a new method using prefabricated retaining wall was proposed and verified. The characteristics of the new method is to replace timber wall as free-sliding steel-lagging and connector. To check its verification and application, laboratory tests such as bending strength, tensile strength, and fatigue strength were carried out. Also, a pilot test in the field and numerical simulations under various ground conditions were performed. From the researches, it is found that the prefabricated retaining wall plate can be superior to the conventional timber lagging plate in the strength. It is also found that the proposed methods can be effective in the reuse of retaining wall plate and safe in the disjoint of wall system. Finally, it is desired that the proposed method will be effective in the reduction of the imported timbers and helpful in the safety of retaining wall construction.

A Study on Securing safety through Behavior Analysis of Earth Retaining Wall (흙막이 가시설의 거동 분석을 통한 안정성 확보 방안에 관한 연구)

  • Kim, Kwang-Leyol;Kim, You-Seong;Kim, Seong-Soo
    • Journal of the Korean Geosynthetics Society
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    • v.12 no.4
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    • pp.11-19
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    • 2013
  • Recently despite the development of analysis program and construction technologies, collapse at the many earth retaining wall construction site of the structure due to the economic and human damage has occurred. The results of geothechnical investigation studies field, it was found to differ from the results of the original design. There may be errors parameters calculated from the results of ground investigation in such a case. And it can be estimated that it is irrational to behavior analysis of the earth retaining wall were analyzed by utilizing the parameters. And in this study, parameters that affect the earth retaining wall the correlations were analyzed using elasto-plastic method. Analysis method was changed various parameters (cohesion, subgrade reaction coefficient, load condition) applied to the elasto-plastic method. And due to a change in the behavior of earth retaining wall materials were analyzed. As a result, the cohesion greatly affects the behavior of earth retaining wall materials in various parameters. For this reason, the results of the geothechnical investigation, confirmation of the actual ground is very important in the design of the earth retaining wall. And, calculating accurate and reasonable of the cohesion of the various parameters is very important.

A Study on the Flowable Backfill with Waste Foundry Sand for Retaining Wall (유동특성을 이용한 폐주물사 혼합물의 옹벽뒷채움재 연구)

  • 조재윤;이관호;이인모
    • Journal of the Korean Geotechnical Society
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    • v.16 no.4
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    • pp.17-30
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    • 2000
  • The objective of this study is to evaluate the lateral earth pressure and the stability of small scale retaining wall with waste foundry sand(WFS) mixtures as a controlled low strength materials (CLSM). Three different types of WFS, like Green WFS, Hurane WFS and Coated WFS, were used in this study, and fly ash of Class F type was adopted. To evaluate the lateral earth pressure and the stability of retaining wall, two different samll scale retaining wall tests, which are called an artificially controlled strain method and a natural strain method, were carried out. In case of an artificially controlled strain method, the coefficient of lateral earth pressure, just after backfilling of WF mixtures, was around 0.8 to 1.0, and most of earth pressure was dissipated within 12 hours. In case of a natural strain method, two steps of stage constructions were employed. The mixtures of Hurane WFS and Coated WFS showed fast decrease of earth pressure due to a relatively good drainage. Judging from the sta bility of retaining wall for overturning and sliding, two steps of stage construction for 2 days were enough to finish the backfill of 6-m height of retaining wall. Also, considering the curling effect of WFS mixtures, the stability of retaining wall increased as curling time increased.

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