• Title/Summary/Keyword: 지지력 평가

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Bearing Capacity of Shallow Foundation on Geogrid-Reinforced Clay (지오그리드로 보강된 점성토사의 얕은 기초의 지지력)

  • Shin, Bang Woong;Das, Braja M.;Shin, Eun Chul;Chung, Kee Taek
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.6
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    • pp.1439-1444
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    • 1994
  • Laboratory model test results for the ultimate bearing capacity and allowable bearing capacity at various settlement levels conducted on a strip foundation supported by geogrid-reinforced clay soil have been presented. For mobilization of the maximum possible load-carrying capacity, the optimum width and depth of the reinforcement layers, and the location of the first layer of reinforcement with respect to the bottom of the foundation have been determined.

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Seam Efficiency of Geotextile and Verification of Allowable Bearing Capacity of Soft Ground (토목섬유 봉합효율과 연약지반 허용지지력 현장검증)

  • Cho, Dae-Sung;Chae, Yu-Mi;Kim, Jae-Hong
    • Journal of the Korean Geotechnical Society
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    • v.37 no.7
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    • pp.25-34
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    • 2021
  • Since the dredging reclaimed land consisting of soft ground is very weak in support, the difficult and complex factors should be considered in the design to calculate accurate bearing capacity of soft ground. Recently, various reinforcement construction methods of soft ground have been designed for dredged landfills, but the stabilities are predicted by calculating conventional Meyerhof (1974) equation for trafficability in soft ground. Conventional equations increase economic costs by underestimating bearing capacity of weak ground in order to ensure constructive safety, so a modified equation has been proposed from the literature. The paper attempts to experiment and compute important factors, such as stitching fiber and seam tensile strength of geotextiles, that are not theoretically considered and can be identified in the field. In addition, The evaluation of the bearing capacity of the modified equation is verified to be stable for trafficability through the plate bearing test performed on site.

Evaluation of Bearing Capacity on PHC Auger-Drilled Piles Using Artificial Neural Network (인공신경망을 이용한 PHC 매입말뚝의 지지력 평가)

  • Lee, Song;Jang, Joo-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.6
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    • pp.213-223
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    • 2006
  • In this study, artificial neural network is applied to the evaluation of bearing capacity of the PHC auger-drilled piles at sites of domestic decomposed granite soils. For the verification of applicability of error back propagation neural network, a total of 168 data of in-situ test results for PHC auger-drilled plies are used. The results show that the estimation of error back propagation neural network provide a good matching with pile test results by training and these results show the confidence of utilizing the neural networks for evaluation of the bearing capacity of piles.

Applicability Evaluation of IGM시s Theory Using the Results of Load Transfer Tests of Drilled Shafts (현장타설말뚝의 하중전이시험 결과를 이용한 IGM 이론의 적용성 평가)

  • 천병식;김원철;서덕동;윤우현
    • Journal of the Korean Geotechnical Society
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    • v.20 no.6
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    • pp.29-40
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    • 2004
  • The bearing capacity of drilled shaft is affected by several factors, such as shaft length, shape, surface roughness, young's modulus of geomaterials and shaft, soil strength, confining stress and so on. However, there has been no design method of drilled shaft considering all factors mentioned above. Moreover, since geomaterials are simply classified as sand, clay and rock, there was no design criterion for IGM (Intermediate Geomaterials). Therefore, the rigorous design approach of drilled shaft was not possible by classical design method. However, since these characteristics were not considered in classical theories, bearing capacity was generally different ken practical value. In this study, the bearing capacity of drilled shaft with the IGM's theory was compared with those of classical theories. The results showed that classical method showed smaller values of bearing capacity than those of field load transfer data. Moreover, the evaluated value of bearing capacity with IGM theory corresponded fairly well with those of field data.

Bearing Capacity Characteristics of the Light Weight Method Used Recycled EPS Beads (폐 EPS 입자를 활용한 경량성토공법의 지지력 평가)

  • Lee, Jongkyu;Lee, Bongjik;Oh, Sewook
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.5
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    • pp.21-29
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    • 2006
  • Light weight filling method prevents settlement of ground by decreasing the weight of fills. This method is increasingly used for it's convenience and workability. Styrofoam is increasingly used as a lightweight filling material in soft ground. The beneficial effects of the use of EPS derive from minimizing the stress increment, increasing the bearing capacity and reducing the settlement. For this study, model test and FEM analysis of bearing capacity is carried out composing two-layered ground with clay in the lower layer and lightweight filling material in upper layer. Based on the results obtained here in this study, it is concluded that the use of recycled EPS beads is acceptable lightweight fill. Light weight fills used for disposal is superior to typical embankment fills in bearing capacity.

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Effect of Configuration of Shaft and Helix Plate on Bearing Capacity of Moderate-size Helical Pile : II. Bearing Capacity Prediction (중소구경 헬리컬 파일의 축과 원판의 형상이 지지력에 미치는 영향 평가 : II. 이론식과 토크에 의한 지지력 예측 비교)

  • Lee, Jongwon;Lee, Dongseop;Na, Kyunguk;Choi, Hangseok
    • Journal of the Korean Geosynthetics Society
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    • v.13 no.2
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    • pp.41-47
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    • 2014
  • Various prediction methods for the bearing capacity of helical piles have been introduced with consideration of both the steel shaft and the helix plates attached to the shaft. In this paper, three representative methods, that is, individual bearing method, cylindrical shear method, and torque correlation method are discussed and compared to each other. The prediction methods were verified by comparing with a series of loading test results performed on moderate-size helical piles from the companion paper. As a result, the measured bearing capacity is greater than the bearing capacity predicted by the cylindrical shear method, but smaller than that of the individual bearing method. In addition, the bearing capacity predicted by the torque correlation method is in good agreement with the measured bearing capacity.

Bearing Capacity of a Square Shallow Foundation with and without Geogrid Reinforcement (Geogrid보강 여부에 따른 정방형 얕은 기초의 지지력에 관한 연구)

  • 신방웅;김수삼
    • Geotechnical Engineering
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    • v.10 no.3
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    • pp.5-16
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    • 1994
  • This paper presents a new method to improve the bearing capacity of a square shallow foundation placed on a sand layer reinforced with geogrids which shows promise for further field work. The geogrid reinforcement will be necessary in the case of machine foundation, embankments for railroads, and foundations of structures in earthquake-prone areas. The ultimate bearing capacity (UBC) for the unreinforced sand and reinforced sand has been compared. Also, the effect of length, spacing, width of reinforcement on increasing the UBC have been evaluated. Based on the present model test results, it appears that significant improvement in the UBC of medium sand can be achieved by geogrid reinforcement.

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Modification of Bearing Capacity Formula Considering Seam Tensile Strength of Geotextile in Soft Ground (연약지반에 포설된 Geotextile 봉합인장강도를 고려한 지지력 수정방정식)

  • Kim, Sun-Hak;Chae, Yu-Mi;Kim, Jae-Hong
    • Journal of the Korean Geotechnical Society
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    • v.35 no.12
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    • pp.59-67
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    • 2019
  • With the increasing use of geotextile mats in dredging and reclaiming work and coastal construction, the assessment of bearing capacity in soft ground has become an important evaluation index for negligent accidents. The review of the allowable bearing capacity of soft ground consisting of inhomogeneous layers by laying geotextile mats and sand mat layers for soft ground improvement is generally compared with the equation of Meyerhof (1974) and Yamanouchi (1985). Mayerhof formula results in economic loss due to underestimation of bearing capacity, and Yamanouchi (1985) formula does not take into account negligent accidents for punching shear failure, so rather high bearing capacity is evaluated. It is considered that economic feasibility and stability will be ensured by proposing a modified formula to calculate the appropriate bearing capacity by applying the seam tensile strength of the geotextile mat to the design standard of soft ground improvement.

Estimation of Bearing Capacity of SIP Pile Installed by Improved Criteria (개선된 기준으로 시공된 SIP 말뚝의 지지력 평가에 관한 연구)

  • Park, Jong-Bae;Kim, Jung-Soo;Lim, Hae-Sik
    • Journal of the Korean GEO-environmental Society
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    • v.5 no.3
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    • pp.5-15
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    • 2004
  • SIP has been widely used as a low noise and vibration piling method in Korea. But the quality control of SIP was not properly settled down and field workers did not fully understand the principle of SIP method. So not a less troubles were raised at construction site and bearing capacity was not fully mobilized. To settle these problems, Korea National Housing Corporation amended the construction and load test criteria of SIP in 2002. After load tests on the SIPs installed in field according to the new criteria, we found that the bearing capacity in field vs the design load ratio increased and bearing characteristics was enhanced than that installed by the former criteria. To consider the enhanced bearing characteristics in the pile design and determine the adequate design criteria, this paper analyzed the accuracy of design criterion which were commonly used in Korea comparing with the load test results. Analysis result shows that Meyerhof criteria(1976) properly simulates the bearing capacity of SIP installed by the new construction and load test criteria.

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