• Journal of the Korean Geotechnical Society
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• v.16 no.2
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• pp.135-143
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• 2000

고강도 H말뚝은 다른 말뚝에 비해 관입성이 우수하며, 경제적으로 시공이 가능하여 도로공사 및 건축공사의 기초말뚝으로 광범위하게 전세계적으로 사용되어지고 있다. 따라서 본 논문에서는 고강도 H말뚝, 강관말뚝 및 PHC 말뚝에 정재하시험과 동재하시험을 실시하여 허용지지력을 비교 분석하였으며, 각각의 말뚝에 대한 동재하시험을 통해 시간경과효과를 평가하였다. 정재하시험과 동재하시험을 비교 분석한 결과 하중-침하곡선이 유사한 것으로 조사되었다. 또한 고강도 H말뚝, 강관 말뚝, PHC 말뚝이 지반내에 향타되었을 때의 허용지지력은 시간이 경과함에 따라 증가하는 것으로 평가되었다. 재하시험 결과 시간경과효과로 인해 지반의 허용지지력이 상승됨을 알 수 있어 앞으로 기초말뚝 설계시 참고자료로 활용할 수 있을 것으로 사료된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.137-143
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• 2020

This study proposes an improvement plan for the evaluation of the bearing capacity and settlement of sewer pipe bases for the improvement of design methods for determining pipe breakage. Under the same conditions, the safety of crushed stone foundation was the lowest. Concrete VR pipe and prefabricated plastic foundations were found to be safe at most excavation depths. The bearing capacity of a rigid pipe foundation was determined by the shape of the foundation, soil conditions, and groundwater, irrespective of the type of foundation. As the depth of the excavation increases, the settlement tends to decrease immediately, and as the diameter of the pipe increases, the settlement tends to increase immediately at the same depth. It is thus reasonable to consider the bearing capacity and the instant settlement amount to solve the problems caused by the settlement of a rigid sewer pipe.

• Journal of the Korean Geotechnical Society
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• v.31 no.8
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• pp.39-49
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• 2015

In this study, a series of centrifuge tests were performed in order to observe the bearing capacity of waveform micropile, a new concept of micropile that uses a modified jet grouting process. A total of six models were considered, conventional micropile, jet grouted pile, and four different shapes of waveform micropiles. The test results indicated that the waveform micropile effectively contributes to the increase of the bearing capacity compared to the micropile without the shear keys. Among the waveform micropiles, the model that has a relatively small space between the shear keys showed the most significant improvement of load capacity. Additionally, the ultimate load capacities of all piles were compared using well-known estimation method. As a result, P-S curve method and total settlement method with 25.4 mm were considered suitable to account ultimate load for the waveform micropile.

• Journal of the Korean Geotechnical Society
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• v.23 no.5
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• pp.89-100
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• 2007

In this study, various field and laboratory tests were performed to investigate the characteristics of shear strength and bearing behavior to be considered in the estimation of stability and trafficability in early stage of stabilization process in marine clay dredged deposit. Site characterization was carried out to grasp the basic properties of the deposit. Field vane test, unconfined compression test and direct shear test were conducted to evaluate the shear strength distribution for varied depths, and the characteristics of shear strength and stress-strain behavior of the crust layer. Plate load tests were also performed to estimate the bearing capacity and to assess load-settlement behavior and failure pattern of the deposit. The bearing capacity was also estimated using previously proposed methods for double-layered clay deposit. The estimated bearing capacity was compared with the results of the plate load tests and then, the applicability of the estimation method was discussed.

• Land and Housing Review
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• v.2 no.2
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• pp.183-188
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• 2011

Recently, the depth of tunnel constructed is getting deeper, which increases difficulty in construction works. Deliberate tunneling techniques are needed as the span and length of tunnels are increased. As one of the technical developments for tunnel, U-shaped and reinforced spider lattice girders are developed by optimizing the spider used in 95mm lattice girder as tunnel steel ribs. In order to evaluate the load bearing capacity of the lattice girder, the 4-point flexural tests are carried out. For the laboratory tests, straight specimens are made for the existing lattice girder and the new lattice girder. The results of the flexural tests showed that the maximum load bearing capacity of the new lattice girders was higher than the traditional one. The load-displacement behavior of the test specimens showed the elasto-plastic behavior in the existing lattice girder and the stress softening behavior in the new lattice girder. It was found that the load bearing capacities are changed depending on the location of the loading points.

• Geotechnical Engineering
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• v.12 no.4
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• pp.101-114
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• 1996

In this study, the characteristics of bearing capacity and deformation of intermediate soils are investigated through centrifuge tests. The experimental parameters are footing width, initial stress condition of soils and relative loading rate defined relationship of loading rate and permeability of soils. It is examined that loading rate influences on the bearing capacities and deformations. Based on the test results, some problem of existing specification are introduced in the view of related loading rates and load intensities. Especially it is showed that load intensities magnitude rlre reversed in the same settlement ratio(s/B(%)), due to partial drained effect as well as loading rates in undrained con dition based on the excess pore pressure and deformations measured under loading.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.5
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• pp.245-254
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• 1993

In this study, the influence of eccentricity on bearing capacity of strip footing has been investigated by the model tests using the carbon rods, the upper bound method of limit analysis, and Meyerhof method of the limit equilibrium method. In applying the upper bound, the failure mechanism based on model tests was used. There was good agreement between the result of model tests and the upper bound method of limit analysis, but Meyerhof method yielded low bearing capacity and underestimated the effect of eccentricity on bearing capacity. Besides, the influences of footing width, embedment depth and base friction on the bearing capacity have been examined.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.5
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• pp.195-202
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• 2021

Offshore wind turbine (OWT) receive a combined vertical-horizontal- moment load by wind, waves, and the structure's own weight. In this study, the bearing capacity for the combined load of the suction foundation of OWT installed on the sandy soil was calculated by finite element analysis. In addition, the stress state of the soil around the suction foundation was analyzed in detail under the condition that a combined load was applied. Based on the results of the analyses, new equations are proposed to calculate the horizontal and moment bearing capacities as well as to define the capacity envelopes under general combined loads.

• Journal of the Korean Geotechnical Society
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• v.33 no.6
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• pp.27-36
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• 2017

Gravel compaction pile method has been widely used to improve the soft ground on the land or sea as one of the soft ground improvement technique. The ultimate bearing capacity of the ground reinforced by gravel compaction piles is affected by the soil strength, the replacement ratio of pile, construction conditions, and so on, and various prediction equations have been proposed to predict this. However, the prediction of the ultimate bearing capacity using the existing models has a very large error and variation, and it is not suitable for practical design. In this study, multiple regression analysis was performed using field loading test results to predict the ultimate bearing capacity of ground reinforced by gravel compaction pile, and the most efficient input variables are selected through evaluation of error by leave one out cross validation, and a multiple regression equation for the prediction of ultimate bearing capacity was proposed. In addition, the prediction error was evaluated by applying artificial neural network using the selected input variables, and the results were compared with those of the existing model.

• Journal of the Korean Geotechnical Society
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• v.22 no.11
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• pp.65-73
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• 2006

Reliability between safety factor and reliability index for driven and bored pile load capacity was analyzed in this study. 0.1B, Chin, De Beer, and Davisson's methods were used for determining pile load capacity by using load-settlement curve from pile load test. Each method defines ultimate yield and allowable pile load capacities. LCPC method using CPT results was performed for comparing results of pile load test. Based on FOSM analysis using load factors, it is obtained that reliability indices for ultimate pile load capacity were higher than those of yield and allowable condition. Present safety factor 2 for yield and allowable load capacities is not enough to satisfy target reliability index $2.0{\sim}2.5$. However, it is sufficient for ultimate pile load capacity using safety factor 3.