• Title/Summary/Keyword: 보강성토

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Examples for Underwater Repair and Strengthening of Bridge Substructures (수중부 하부 구조의 보수 보강)

  • 유동우
    • Magazine of the Korea Concrete Institute
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    • v.13 no.2
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    • pp.38-43
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    • 2001
  • 교량 하부구조 특히 교각 및 기초의 경우는 지반 또는 수중에 묻혀 있기 때문에 손상을 발견하기도 어렵고 또한 손상의 보수 및 보강이 곤란한 경우가 많다. 하부구조의 손상은 지반의 마모, 침하, 측방유동토압, 하상세굴, 홍수류, 선박 및 유하물에 의한 충격, 지진 등의 여러 원인에 의하여 발생된다. 이러한 손상은 지표수 및 지하수 배제공, 성토공, 지반개량공, 단면보수공, 세굴방지공, 내진보강공 등에 의하여 보수 및 보강이 행하여 진다. 본 고에서는 이러한 하부구조의 보수.보강공법 중 수중부에 실시되는 방법에 대하여 소개하고자 한다.

Investigation on Support Mechanism of Geogrid-Encased Stone Columns in Soft Ground (연약지반에 시공되는 지오그리드 감쌈 스톤컬럼의 하중 지지 메카니즘에 관한 연구)

  • Yoo, Chung-Sik;Kim, Sun-Bin
    • Journal of the Korean Geotechnical Society
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    • v.24 no.12
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    • pp.93-101
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    • 2008
  • This paper presents the results of numerical investigation on support mechanism of geogrid-encased stone columns for use in soft ground improvement. A number of cases were analyzed using a 3D stress-pore pressure coupled model that can effectively model construction sequence and drainage as well as reinforcing effects of geogrid-encased stone columns. The results indicated that the geogrid encasement provides additional confinement effect that reduces vertical stress in the soft ground, thus resulting in less excess pore water pressures and associated settlement. Also revealed was that such a confinement effect depends on encasement length and stiffness of geogrid. It is also shown that there exist critical encasement length and stiffness of geogrid for a given condition.

Research about Application Possibility of Afforestation Reinforced Soil Steep Slope by Nonwoven Geotextile (부직포를 활용한 급경사 녹화보강토공법의 적용 가능성에 관한 연구)

  • Cho, Yong-Seong;Koo, Ho-Bon;Lee, Choon-Kil
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.4C
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    • pp.239-245
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    • 2006
  • The steep slopes have been increased of new roads, industrial site development and large scale residential development. The preservation administration and steep slope construction are currently investigated by many researchers in Korea. However, concrete retaining wall or reinforced soil (i.e. Block or Pannel) are being applied for the steep slope, which results in the front face form of the structure being limited. This research investigates the method that can make up afforestation environment-friendly circumstances during the construction of steep slope structure. It is considered that steep slope reinforced structure would be possible based on the monitoring results about earth pressure, horizontal displacement and consolidation quality generated during the construction of whole constructing reinforced structure. Also, there no problems in grassy surface, drainage, and deformation in spite of rainy season after construction period and until now. So that the seeding soil layer surface reinforced soil method could be adopt for steep slope reinforced structure and others.

Stability Analysis of the Reinforced Embankment on Soft Foundations using the Limit Equilibrium Method (한계평형법에 의한 연약지반 보강성토의 안정해석)

  • 고남영;고홍석
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.37 no.5
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    • pp.101-110
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    • 1995
  • The use of geotextile as reinforced materials in Soil structures has become widespread throughout the world. Geotextile reinforcement has been used in retaining walls, slope of embankment and especially soft foundation, etc. In the past, however, its design and construction have been performed empirically. In this study, to investigate of the effect of geotextiles reinforced slope of the embankment on a very soft foundation, a limit equilibrium analysis program calculating the safety factor of embankment on very soft foundation was developed. The study was focussed on such factors as type of geotextile, tensile strength, amount of reinforcement, and inclination of embankment. And the 4imit equilibrium analysis program was written on the basis of Low's slope stability theory with some modification. The following conclusions were drawn from this study. (1) The orientation of reinforcement can be assumed either horizontal or tangential to the slip circle. The factor of safety with tangential reinforcement is larger than that with the horizontal reinforcement. (2) In general, the factor of safety increases, as the slope reduces. However, it is preferable to use geotextiles with higher tensile strength rather than to reduce the slope of the embankment, because it is difficult to adjust the slope as desired. (3) The factor of safety obtained by numerical computation is affected only by the tensile strength, but not by the type of the geotextile.

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A Study on Influence of Constructed Bridge Abutment in Landfill Slope under Laterally Displacing (측방유동 발생 시 성토사면에 시공된 교대의 영향에 대한 연구)

  • Lee, Hangyu;Hong, Jongouk;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.12
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    • pp.31-41
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    • 2013
  • The damage caused by lateral movement occurs frequently on site where abutment or retaining wall was built on soft ground along with embankment behind and the study on stability of abutment against lateral movement has been mostly focused on soft ground. However lateral movement occurs not only on soft ground but also on embankment slope which causes the impact on structure. The bridges built in Korea are mostly on mountainous area than soft ground. This study is intended to analyze the ground behavior resulting from lateral movement using finite element analysis method to the section as well as propose the basic data for abutment design on embankment slope through the analysis of the outcome of reinforcement method. As a result, when it comes to the reinforcement with soil surcharge and stabilized pile in slope, lateral movement was reduced by 4~30% and displacement on bearing shoe on abutment was reduced by 2~13%. On the contrary, when reinforced with EPS, lateral float was reduced by 97% and maximum horizontal displacement of bearing shoe on abutment was reduced by 95%. Thus, it's necessary to identify the design technique which is applicable to domestic condition through additional tests and more reliable study using numerical analysis and comparing the measured values shall follow.

A Study on Deformation of Soft Clay Foundation by Embankment Construction (제방축조에 의한 연약점토지반의 변형해석에 관한 연구)

  • 정형식;황영철
    • Geotechnical Engineering
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    • v.9 no.2
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    • pp.55-64
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    • 1993
  • When earth structures such as dykes or embankments are constructed on very soft clay foundation, unexpectedly large deformations of earth structures as well as clay foundation are encountered during and after construction. The final constructed section is composed of a portion of embankment above the existing ground level and that which penetrated into the soft foundation soil. This study is aimed to correctly estimate the shape of earth structures which penetrate some depth into the soft clay foundation. In this study the methods to predict penetration depth and deformation shape of embankment section after dumping of construction material. Model tests were carried out to prove the developed theory and FEM analysis. And when the mat is added, reinforcement effect was markedly noticed.

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Applicability of the Pile-Supported Embankment in Korea (성토지지말뚝공법의 국내 적용성 분석)

  • Lee, Il-Wha;Kim, Seung-Sun;Lee, Joo-Gong;Shim, Shung-Kyu;Lee, Su-Hyung
    • Journal of the Korean Geotechnical Society
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    • v.32 no.3
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    • pp.5-13
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    • 2016
  • Stability analysis was conducted to analyze the application of pile-supported embankment to concrete slab track on the soft ground in Korea. Pile efficiency and tension of geosynthetics in accordance with the hight of embankment and the depth of soft soil were carried out by theoretical and numerical methods. Theoretical method predicted more conservatively than the numerical method for all the cases presented herein. The settlement stability is satisfied to allowable criteria of high speed railway in Korea. The pile-supported embankment has great potential for application to soft ground condition.

An Experimental Study on Geotextile Effects as Reinforcement and Vertical Drain Materials (보강재(補强材) 및 배수촉진재(排水促進材)로서 Geotextile 의 효과(効果)에 관한 실험적(實驗的) 연구(硏究))

  • Kim, Soo Il;Yoo, Ji Hyeung;Cho, Sam Deok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.2 no.4
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    • pp.39-47
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    • 1982
  • Geotextile effects as reinforcement and vertical drain materials are studied through the laboratory model embankments on weak clays. The experiments are carried out in four stages; no woven fabrics between clay-crushed stone boundary, fabrics between boundary with no initial pretensioning of fabrics, and fabrics between boundary with two different initial pretensionings of fabrics. In all stages, vertical drains utilizing non-woven fabrics are installed in the clay layer in square pattern to accelarate the consolidation. The experimental model has plane dimensions of $32cm{\times}330cm$. The height for the clay container is 60 cm. The 47 cm height of crushed stone embankment is constructed over the 50 cm deep clay layer. The time dependent pore pressures are measured utilizing the 8 piezometers installed symmetrically on both sides of the wall at different heights. The time dependent deformations are measured utilizing the LED indicating lamp matrix inserted in the crushed stone embankment and the dialgauges put on top of the clay layer where the crushed stones are not laid. The measurements are carried out for 10 days which is equivalent to the time required for the primary consolidation. Through the experimental study, an analytical procedure is developed to predict the time dependent embankment settlement even if the top of the clay layer is reinforced with woven fabrics. This can be done through measuring the maximum pore pressures developed in the clay layer and comparing with the theoretical maximum pore pressures when no reinforcing fabrics are employed.

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