• Title/Summary/Keyword: 보강지반

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Evaluation of Reinforcing Effects of Pressure-Injected Grouting Nail in Weathered Rock (풍화암 사면에서의 압력분사 그라우팅 네일 보강 효과 연구)

  • Hwang, Young-Cheol;Kim, Nak-Young
    • Journal of the Korean GEO-environmental Society
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    • v.3 no.1
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    • pp.47-55
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    • 2002
  • The slope reinforcing method utilized in this paper reinforces the ground overall by means of filling borehole as well as permeating grout material into ground by injecting it through the grouting pipe. In order to reflect these characteristics to design, not only the ground reinforcing effect by the structural material itself but also the ground strength improvement effect by the grouting injection must be quantitively evaluated. But precedent research of it has been insufficient. Therefore, the slope reinforcing method was applied to the weathered rockmass slope situated in the highway in order to analyze reinforcing effect and the instrumentation of slope was performed. Through analysis of this field test, the slope reinforcing method was proved to be effective and back analysis method based on instrumentation values of slope was proposed to apply to reinforcing design. In this paper, the effectiveness of reinforcing method was certified through proposed back analysis.

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Numerical Model Study on a Scheme to Restrain Deformation of a Conduit with Flexible Joints(II) : Effectiveness of Concrete Bedding Reinforcement (연성이음관의 변형억제방안에 관한 수치모델연구(II): 콘크리트베딩 보강효과)

  • 손준익;정하익
    • Geotechnical Engineering
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    • v.7 no.4
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    • pp.15-24
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    • 1991
  • This paper reports the application study of the concrete bedding reinforcement under a buried conduit with flexible joints subjected to differential settlement via a finite elemen modeling. The reinforcement of concrete bedding helps to minimize the differential settlement between the adjoining conduit segments. Three different field conditions have been considered. The settlement pattern and deformation slope have been evaluated for each boundary condition. The analysis results are compared for both non-reinforced and reinforced cases to measure the effectiveness of concrete bedding reinforcement for restraining deformation of a conduit with flexible joints.

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Stability Analysis of Soil Nailed Slope by Discrete Element Method (개별요소법을 이용한 지반네일에 의해 보강된 굴착사면의 안정해석)

  • 김주용;김준석
    • Geotechnical Engineering
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    • v.11 no.4
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    • pp.49-62
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    • 1995
  • Soil nailing has been widely rosed during the last two decades to stabilize sheep excavated slopes in several countries. In thin study, the discrete element method has been applied to evaluate the stability of the reiuorced slope. This method is capable of not only estimat ins tensile and sheer stresses mobilized in nails but also providing individual safety factors of soil and nails, It has been assumed that the nailed slope be comprised of slices connected with elastoplastic twinkler springs. A reasonable mechanism is applied for representing the behavior between nails and adj scent soils. Taking into account for the bequence of construction the developed method well predicts the measured tensile forces developed in nails so that it is possible to appropriately evaluate the overall safety factor.

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Bearing Capacity Characteristic of Dredged and Reclaimed Ground Reinforced by Bamboo Net (대나무 망으로 보강된 준설매립지반의 지지력 특성)

  • Kang, Myoung-Chan;Yang, Kee-Sok;Lee, Song
    • Journal of the Korean Geotechnical Society
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    • v.22 no.8
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    • pp.5-11
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    • 2006
  • A series of large scale plate loading tests are performed to assess bearing capacity characteristic of dredged and reclaimed ground that is reinforced by bamboo net and geotextile as a surface strengthen method. Bearing capacity ratio is distributed from 3.46 to 6.03 for bamboo net and from 2.19 to 3.59 for Geotextile In case of bamboo net, BCR was obtained from 1.6 to 1.7 times than Geotextile. As the comparison of each bearing capacity from test and theory shows, bearing capacity theory for geotextile was not suited for bamboo net. The bearing capacity analysis reinforced by bamboo net shows a good relationship between sand mat thickness (H) / bamboo net space (S), and bearing capacity ratio (BCR).

A Study on Bearing Capacity according to the Number of Reinforcement Layers in Sandy Ground Reinforced by Mats of Equal-intervals (등간격의 매트로 보강된 모래지반의 보강층수에 따른 지지력에 관한 연구)

  • 임종철;박성재;주인곤;이재열;이민희
    • Journal of the Korean Geotechnical Society
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    • v.15 no.6
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    • pp.201-217
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    • 1999
  • Bearing capacity of soil can be improved by several conventional ground improvement techniques like stabilization and compaction. In recent time, the use of reinforced soil has become popular due to the availability of durable strong geosynthetic materials. In this papers, through the laboratory model tests on sandy ground reinforced by mats about the strip footing under plane strain condition, the effects of bearing capacity improvement and behaviour of sandy ground were observed. And bearing capacities calculated by proposed method and measured by tests were compared.

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A Study on Anisotropic Reinforcing Mechanism of Umbrella Arch Reinforcement Method in Tunnelling (터널 보강용 강관 다단 그라우팅 공법의 이방성 보강 메카니즘 규명에 관한 연구)

  • 배규진;신휴성;최용기
    • Journal of the Korean Geotechnical Society
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    • v.19 no.6
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    • pp.245-259
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    • 2003
  • This paper deals with an Umbrealla Arch Reinforcement Method (UARM) in tunnelling. It is known that the mechanism of the reinforcement system is too complex to be simulated in existent finite element (FE) frameworks when considering its complex geometry of pipe arrangements and contribution of each component of the reinforcement to reinforcing effect. In this study a 3-D elastoplastic FE procedure is, therefore, proposed by introducing homogenisation technique, which is used to define mathematically elastic as well as elastoplastic characteristics of a reinforced ground material as a composite. A number of practical suggestions are addressed considering staged constructions of tunnels. For illustrative purposes, a series of parametric studies are undertaken and anisotropic characteristics of the reinforced ground as well as effects of the reinforcement on tunnel convergences are investigated. It is found that the reinforced ground material defined in homogenisation framework has its mechanical characteristics reasonably representing inherent geometrical and quantitative characteristics of each of constituents.

An Analysis of the Internal Deformation Behaviors of Geosynthetic Reinforced Soil Walls used Clayey Soil as Backfills (뒤채움재로 점성토를 사용한 보강토벽의 내적 거동 분석)

  • Kim, Heung-Ki;Kim, You-Seong
    • Journal of the Korean GEO-environmental Society
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    • v.6 no.2
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    • pp.39-49
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    • 2005
  • In this study, the fifteen month behavior of two geosynthetic reinforced walls which was constructed on the shallow weak ground was measured and analyzed. The walls were backfilled with clayey soil obtained from the construction site nearby, and the safety factors obtained from general limit equilibrium analysis were less than 1.3 in both wall. The measured and analyzed data were horizontal earth pressures, strain of reinforcements, and excess pore water pressures. The used reinforcements were nonwoven geotextile, woven geotextile and geogrid. Although the length of reinforcement was only 30% of wall height and the safety factors of the walls were less than 1.3, the walls were constructed without any problems on the such weak ground. The analysis results showed that the maximum strain of reinforcements were negligible and the strain was between 2.3 and 6.0% according to tensile characteristic of the reinforcements. The excess pore water pressure was not changed due to the rainfall and the horizontal earth pressures in upper and lower part of the walls were larger than the active and the rest pressure.

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Reinforcing Effect of Pre-Tensioned Rock Bolts in the Jointed Rocks Condition (록볼트 긴장에 의한 수평절리암반의 보강효과)

  • An, Joung-Hwan;Lee, Sang-Duk
    • Tunnel and Underground Space
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    • v.19 no.5
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    • pp.388-396
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    • 2009
  • Rock bolt is one of the most important supports for tunnelling to prevent excessive ground relaxation at the primary tunnel excavation stage. It forms a ground arch band by confining the ground around a tunnel. Rock bolt has various effects, such as support or hanging effect, internal pressure effect, arching effect, ground improvement effect etc. Most studies on rock bolt focused on the concept of support, but only a few researches on the ground reinforcing effect by pre-tensioning a rock bolts. In this study, large scale model tests are performed to investigate the ground reinforcing effect of rock bolts for regularly jointed rocks. Simple beam model was built to find out the reinforcing effect of jointed rocks, which was reinforced by pre-tensioned rock bolts. Settlement of model beam was analyzed through measuring its sagging for various installation intervals.

Load Transfer Analysis of Drilled Shafts Reinforced by Soil Nails (Soil Nail로 보강된 현장타설말뚝의 하중전이 분석)

  • 정상섬;함홍규;이대수
    • Journal of the Korean Geotechnical Society
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    • v.20 no.1
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    • pp.37-47
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    • 2004
  • In this study the load distribution and settlement of soil nailed-drilled shafts subjected to axial loads were evaluated by a load-transfer approach. Special attention was given to the reinforcing effects of soil nails placed from the shafts to surrounding weathered- and soft-rocks based on an analytical study and a numerical analysis. An analytical method that takes into account the number, the positions on the shaft, the grade, and the inclination angle at which the soil nails are placed was developed using a load transfer curve methods. Through the comparative study, it is found that the prediction by present approach simulates well the general trends observed by the in-situ measurements and numerical results SHAFT 4.0. It is also found that the reinforcing effects of soil nails increases in the order of hard-, soft- and weathered-rock since the ultimate shaft resistance far large bored piles in weathered rocks is fully mobilized after small displacements of the shaft, compared to the soft- and hard-rocks and subsequently the side resistance is transferred down to the soil nails.

A Study on the Reinforcement of the Soil Blocking Facilities Due to Water Pipe Rupture Accident (상수관 파열 사고로 인한 흙막이 가시설 보강사례 연구)

  • Woo, Jong-Tae
    • Proceedings of the Korean Society of Disaster Information Conference
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    • 2023.11a
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    • pp.241-243
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    • 2023
  • 아파트 신축공사 흙막이 가시설 현장에 근접 매설된 상수관의 누수 및 파열 사고로 터파기 공사 현장에 토사 유실 및 지반 함몰이 발생되었으며, 흙막이 가시설의 토류판이 파손되었다. 흙막이 가시설의 안정성 확보를 위해 벽체구간은 레이커로 보강하고 사보강재는 1단과 2단을 묶어 힘을 분산시키고 종방향으로 보강 및 토류판 보강을 시행하였다.

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