• Title/Summary/Keyword: Embankment structure

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Centrifuge Modelling of Bridge Abutment Foundation on the Sloped Ground (경사지반에 위치한 교대기초의 원심모델링)

  • Yoo, Nam-Jae;Jun, Sang-Hyun;Hong, Young-Kil
    • Journal of Industrial Technology
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    • v.27 no.B
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    • pp.209-214
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    • 2007
  • This paper is the research result about centrifuge model experiments of investigating the behavior of bridge abutment on the sloped ground. Ground condition of the studied site was the bridge abutment with pile foundation adjacent to the slope. The pile foundations was supported on the soft rocks covered with the embankment. Evaluating the behavior of such a complicate ground and structure conditions was not easy so that the centrifuge modelling was performed to find the overall behavior of them. Layout of centrifuge model experiment was simplified to simulate easily the actual behavior of very complicate site condition. Construction process in field such as ground excavation for footing foundation, installation of piles, placement of footing and bridge abutment, backfilling and surcharge loading eas duplicated in the centrifuge model experiment. Consequently, the stability of the piled bridge abutment adjacent to the slope of embankment was evaluated throughout centrifuge modelling.

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Assessment of Stability of Railway Abutment Using Geosynthetics

  • Kim, Ja-Yeon;Kim, Ji-Hwan;Cho, Kook-Hwan
    • International Journal of Railway
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    • v.9 no.1
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    • pp.15-20
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    • 2016
  • An approach section on an abutment is located between the soil embankment and the structure, which may cause an uneven surface due to different settlement between the abutment and the soil embankment. This study proposes a new type of wall which separates the abutment from the backfill material using mechanically stabilized wall. A new type of keystone which incorporates geotube and wire mesh is proposed and evaluated. Numerical analyses were performed to investigate the applicability of the proposed keystone type, which incorporates Geosynthetic. The maximum horizontal displacements along GRS wall faces, settlements at the top of pavement and track bed, and tensile forces applied on geotextiles under traffic loads were investigated. The results of the numerical analysis showed that the proposed wall can be used for highway and high-speed railway abutment.

Study on Lateral Flow of Soft soils by Field Measurement and Numerical Analysis (계측 및 수치해석에 의한 연약지반의 측방유동 연구)

  • Kim Dae-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.6 no.5
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    • pp.423-427
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    • 2005
  • In this paper, the lateral displacement of soft soil was measured in pier structure. The result was compared and investigated with the result of numerical analysis. The lateral displacement of soft soil was affected by lateral flow of soft soil due to embankment rather than settlement, and rapidly occurred at the embankment and preloading phases. The measurement and the numerical analysis showed very similar trend of lateral displacement but the magnitude was larger in numerical analysis than in measurement.

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Prediction model of service life for tunnel structures in carbonation environments by genetic programming

  • Gao, Wei;Chen, Dongliang
    • Geomechanics and Engineering
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    • v.18 no.4
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    • pp.373-389
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    • 2019
  • It is important to study the problem of durability for tunnel structures. As a main influence on the durability of tunnel structures, carbonation-induced corrosion is studied. For the complicated environment of tunnel structures, based on the data samples from real engineering examples, the intelligent method (genetic programming) is used to construct the service life prediction model of tunnel structures. Based on the model, the prediction of service life for tunnel structures in carbonation environments is studied. Using the data samples from some tunnel engineering examples in China under carbonation environment, the proposed method is verified. In addition, the performance of the proposed prediction model is compared with that of the artificial neural network method. Finally, the effect of two main controlling parameters, the population size and sample size, on the performance of the prediction model by genetic programming is analyzed in detail.

A Computer Program for 2-D Fluid-Structure-Soil Interaction Analysis (2차원 유체- 구조물-지반 상호작용해석 전산프로그램)

  • 김재민
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.04a
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    • pp.427-434
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    • 2000
  • This paper presents a computer program for a 2-D fluid-structure-soil interaction analysis. With this computer program the fluid can be modeled by a spurious free 4-node displacement-based fluid element which uses rotational penalty and mass projection technique in conjunction with the one point reduced integration scheme to remove the spurious zero energy modes. The structure and near field soil are discretized by the standard finite elements while the unbounded far field soil are discretized by the standard finite elements while the unbounded far field soil is represented by the frequency dependent dynamic infinite elements. Sine this method models directly the fluid-structure-soil system it can be applied to the dynamci analysis of 2-D liquid storage structure with complex geometry. For the purpose of verification dynamic analyses for tanks on a rigid foundation and on compliant embankment are carried out. Comparison of the present results with those by ANSYS program shows good agreement.

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Case study on Construction and Improvement of Rahmen Structures in Deep Soft Clay Deposit (대심도 연약지반에 설치된 라멘 구조물의 시공 및 보강사례)

  • Lee, Sa-Ik;Choi, Young-Chul;Yoo, Sang-Ho;Kim, Tae-Hyung;Kim, Sung-Ryul
    • Journal of the Korean Geosynthetics Society
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    • v.13 no.1
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    • pp.85-92
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    • 2014
  • Structures that have constructed in soft clay might suffer from many issues related to consolidation settlement or lateral movement of soft-clay during long-term period. Therefore, it is important to establish proper design and construction processes related to site investigation, soil improvement, construction management, and so on. This case study focused on the construction of the rahmen structure supported by pile foundations. Especially, the structure in this case had been constructed without improving underlying soft clay and before constructing backfill embankment due to the limited construction time and the traffic connection of the old road crossing new highway. Therefore, in order to satisfy the structural stability, the construction processes and countermeasure methods were carefully planned based on the results of preliminary numerical analyses and monitoring of ground behaviors. Through the trial and error precess during the construction, the structures had been successfully constructed.

Reinforcement Effect of Marine Structure Foundation by Column Jet Method (CJM 그라우팅에 의한 호안구조물의 기초보강효과)

  • 천병식;양형칠
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2001.10a
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    • pp.128-131
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    • 2001
  • The purpose of this study is to investigate the application of Column Jet Method(CJM) as countermeasure against settlement and slope sliding of existing marine structure due to embankment load behind reclaimed revetment. CJM is to make high-strengthened body by compacting and grouting cement mortar after forming artificial space in the ground with ground relaxition machine or high pressure water jetting. Before the ground was reinforced by CJM, the result of slope stability analysis was not satisfy the allowable safe ratio, but after the ground was reinforced by CJM, the stability of slope was over the allowable safe ratio and stable, Therefor, the application of CJM to restraint settlement and sliding of marine structure was very satisfactory.

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Estimating Sea Surface Temperature Change after Tide Embankment Construction using Landsat Data (방조제 건설에 의한 해수면 온도 변화 추정)

  • Shin, Dong-Hoon;Lee, Kyoo-Seock
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.4
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    • pp.224-232
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    • 2006
  • This study investigates to detect Sea Surface Temperature (SST) and land cover change after tide embankment construction using Landsat Thematic Mapper (TM) Thermal Infrared (TIR) band data at Shihwa Lake and surrounding area. SST measurement is important for studies of both the structure of the ocean and as the thermal boundary between the ocean and the atmosphere. Since 1970s, the derivation of SST by satellite remote sensing (RS) has been applied to earth surface using Advanced Very High Resolution Radiometer (AVHRR) and Landsat TM. However, AVHRR has restriction in deriving SST in the area whose shoreline is complicated like western coast in South Korea because of coarse spatial resolution. The TIR band of TM images can be used to detect SST change whose shoreline is complicated and narrow like the study site. Thus, multi-temporal TM images were used for SST change detection in this study.

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A study on the performance-based design methodology for tunnels through case study on the tunnel built by the prescribed design (사양중심의 터널 설계 사례 연구를 통한 성능기반 터널 설계 방안에 관한 고찰)

  • Hur, Jin-Suk;Kim, Seung-Ryull;Hwang, Je-Don;Seo, Young-Wook;Jung, Myung-Keun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.15 no.4
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    • pp.415-429
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    • 2013
  • Performance-based design is becoming a key word for structure design in architectural and civil engineering spheres. In this paper, the need of the performance-based design, especially for tunnels, was enhanced by case study on the largely deformed cut-and-cover arch tunnel built by the prescribed design. In addition, this paper introduces effective method of subdivision on tunnel performance to help field engineer's comprehension. Case study dealing with the issue of typical backwards problem in geotechnical engineering was examined. First of all, the outline of the damaged culvert as well as the surrounding embankment is in detail described. The background, together with the cause of damage, is discussed based on the results of site investigation. Secondly, it was attempted to elucidate the deformation mechanism of the embankment by means of numerical analysis, and the countermeasures are proposed. Finally, the stability of the embankment with the countermeasures was evaluated.

Behavior Analysis of Particle Crushing about Sabkha Layer under Hydrotest (Sabkha층의 Hydrotest 시 입자파쇄 거동분석)

  • Kim, Seokju;Han, Heuisoo
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.9
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    • pp.57-65
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    • 2013
  • Carbonate sands can be crushed under low confining pressure to achieve high compressibility. So particle crushing has significant influence on characteristics of strength and deformation. Trial embankment and hydrotest are conducted on Sabkha layer, consisting of carbonate sand to build tank structure. In this paper the settlement behavior was analyzed from each test. Particle crushing happened from 80 to 170kPa stress under compression test, and calcium was detected from chemical test. The test result came out Sabkha soil was very weak and easy to be crushing. About trial embankment test, particle crushing was not happen, and then extinction of pore water pressure and settlements were finished just during 2 days. On the other hand, the long-term settlement was happened in hydrotest. So the two test results did not correspond to each other. If loading stress is higher than yielding stress, instant settlement and secondary compression settlement are happened as a result of the particle crushing.