• Journal of the Korean GEO-environmental Society
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• v.5 no.4
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• pp.33-45
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• 2004

In the present study, more systematic laboratory model tests under various conditions are carried out to investigate load-sharing characteristics among the granular pile and adjacent soils and bearing capacity characteristics with different pile lengths. Further to evaluate effects of both a loading area and a spacing of pile installation on the bearing capacity and bearing capacity characteristics of each pile in group, model test results are also analyzed for the purpose of an efficient design of granular compaction piles. From the analysis of the model test results, it is found that the ultimate capacity of granular compaction group piles increases with a decrease in the installation distance among granular piles. It is also found that the dominant failure mode of the granular compaction piles is bulging failure. It is further realized that the length of a granular pile could not significantly affect on the ultimate granular pile capacity.

• Geotechnical Engineering
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• v.9 no.1
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• pp.31-44
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• 1993

Model tests in calibration chamber with open -ended steel pipe pile have been performed in sand deposit to clarify effect of soil plug on bearing capacity, load transfer mechanisms in soil plug, and behavior of soil plug under dynamic and static conditions. Model piles were devised so that bearing capacity of open -ended pile could be measured separately into outside skin friction, inside skin friction due to soil plug -pile interaction and end bearing force on the section of steel pipe pile. It may be concluded, form the test results, that the plugging level of open -ended pile is more correctily defined by specific recovery ratio, y, rather than by plug length ratio, PLR, and the major part of inside skin friction is generated within the range of three times as long as the inner diameter of the pile from the pile tip. The ratio of inside skin friction to total bearing capacity is much larger than that of outside skin friction to total bearing capacity. Therefore, the bearing capacity of pile could not be well predicted, unless the inside skin friction is properly taken into account.

• Journal of the Korean GEO-environmental Society
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• v.14 no.3
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• pp.29-34
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• 2013

In this paper, numerical analyses were conducted on piled raft foundation settlement and pile bearing characteristics in soft ground. Results obviously showed longer and larger piles developed end bearing capacity values, but also showed the load of the central pile is larger than the surrounding piles in a group formation. Additionally, after pile yielding, the load carrying capacity exists as a raft. Moreover, results showed no transverse displacement according to embedment depth for the single pile case, but larger transverse displacements for deeper embedment depths.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.3
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• pp.156-162
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• 2010

When eccentric or inclined load acts on foundation of the port & harbor structures, partial safety factors of bearing capacity limit state were estimated using reliability analysis. Current Korean technical standards of port and harbor structures recommend to estimate the geotechnical bearing capacity using the simplified Bishop method. In practice, however, simple method of comparing ground reaction resistance with allowable bearing capacity has been mostly used by design engineers. While the simple method gives just one number fixed but somewhat convenient, it could not consider the uncertainty of soil properties depending on site by site. Thus, in this paper, partial safety factors for each design variable were determined so that designers do perform reliability-based level 1 design for bearing capacity limit state. For these, reliability index and their sensitivities were gained throughout the first order reliability method(FORM), and the variability of the random variables was also considered. In order to verify partial safety factors determined here, a comparison with foreign design codes was carried out and were found to be reasonable in practical design.

• Journal of the Korean GEO-environmental Society
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• v.5 no.2
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• pp.51-62
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• 2004

Granular compaction piles have the load bearing capacity of the soft ground increase and have the settlement of foundation built on the reinforced soil reduce. The granular compaction group piles also have the consolidation of the soft ground accelerate and have the liquefaction caused by earthquake prevent using the granular materials such as sand, gravel, stone etc. However, this method is one of unuseful methods in Korea. The Granular compaction piles are constructed by grouping it with a raft system. The confining pressure at the center of bulging failure depth is a major variable in relation to estimate for the ultimate bearing capacity of the granular compaction piles. Therefore, a share of loading is determined considering the effect of load concentration ratio between the granular compaction piles and surrounding soils, and varies the magnitude of the confining pressure. In this study, method for the determination of the ultimate bearing capacity is proposed to apply a change of the horizontal pressure considering bulging failure depth, surcharge and loaded area. Also, the ultimate bearing capacity of the granular compaction piles is evaluated on the basis of previous study on the estimation of the ultimate bearing capacity and compared with the results obtained from laboratory scale model tests. And using the result from laboratory model tests, it is studied increase effect of the bearing capacity on the granular compaction piles and variance of coefficient of consolidation for the ground.

• Journal of the Korean Geotechnical Society
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• v.17 no.4
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• pp.289-299
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• 2001

본 연구는 균질 및 2개층 비균질지반에서 사질토지반 상에 놓인 정방형 기초의 극한지지력과 침하에 대하여 고찰하였다. 본 연구는 얕은기초의 거동에 대한 정방형 기초의 크기, 지반 상대밀도, 기초 폭에 대한 상부층의 두께 비(H/B), 상부층 아래 경계면의 경사($\theta$) 그리고 지반강성비의 영향을 규명하기 위하여 모형실험을 수행하였다. 동일 상대밀도에서 지지력 계수($N_{{\gamma}}$)는 일정하지 않으며 기초 폭에 직접적으로 관련되며 지지력계수는 기초 폭이 증가함에 따라 감소하였다. 기초크기의 영향과 구속압력의 영향을 고려하는 Ueno 방법에 의한 극한지지력의 예측값은 고전적인 지지력 산정식보다 더 잘 일치하며 그 값은 실험값의 65% 이상으로 나타났다. $\theta$=$0^{\circ}$인 2개층 지반의 결과에 근거하여, 극한지지력에 대한 하부층 지반의 영향을 무시할 수 있는 한계 상부층 두께는 기초 폭의 2배로 결정되었다. 그러나, 73%의 상부층 상대밀도인 경우는 침하비($\delta$B) 0.05 이하에서만 이 결과가 유효하였다. 경계면이 경사진 2개층 지반의 결과에 근거하여, 상부층의 상대밀도가 느슨할수록 그리고 상부층의 두께가 클수록 극한지지력에 대한 경계면 경사의 영향은 크지 않는 것으로 나타났다. 경계면의 경사가 증가함에 따른 극한침하량의 변화는 경계면이 수평인 경우($\theta$=$0^{\circ}$)를 기준으로 0.82~1.2(상부층 $D_{r}$=73%인 경우) 그리고 0.9~1.07(상부층 $D_{r}$=50%인 경우) 정도로 나타났다.Markup Language 문서로부터 무선 마크업 언어 문서로 자동 변환된 텍스트를 인코딩하는 경우와 같이 특정한 응용 분야에서는 일반 문자열에 대한 확장 인코딩 기법을 적용할 필요가 있을 수 있다.mical etch-stop method for the etching of Si in TMAH:IPA;pyrazine solutions provides a powerful and versatile alternative process for fabricating high-yield Si micro-membranes. the RSC circle, but also to the logistics system in the SLC circle. Thus, the RSLC model can maximize combat synergy effects by integrating the RSC and the SLC. With a similar logic, this paper develops "A Revised System of Systems with Logistics (RSSL)" which combines "A New system of Systems" and logistics. These tow models proposed here help explain several issues such as logistics environment in future warfare, MOE(Measure of Effectiveness( on logistics performance, and COA(Course of Actions) for decreasing mass and increasing velocity. In particular, velocity in logistics is emphasized.

• 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.

• Journal of the Korean Geosynthetics Society
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• v.5 no.1
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• pp.9-14
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• 2006

The reinforced soil retaining wall structures of serious types with environmental are widely expanding more and more in Korea, which divided conventional type's reinforced soil retaining wall on segmental retaining wall. The causes of most crack occurred at block in reinforced soil retaining wall structure caused by the differential settlement of foundation. It is difference of settlement for significant factor that with overall slope stability. In this study, design assessment of foundation bearing capacity related to differential settlement of foundation ground was considered. And, also, through case study, the countermeasure methods and its application were suggested that the bearing capacity of foundation had to stabilize. The foundation ground in charge of bearing capacity should be affected by the resisting force of sliding, because the foundation parts of reinforced soil retaining wall were belongs to potential slope sliding area in overall stabilizing including retaining wall structures. Therefore, the analyzing or the designing of bearing capacity for foundation should be considered control capacity on the overall slope sliding.

• Journal of the Korean Geotechnical Society
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• v.31 no.7
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• pp.29-39
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• 2015

The vertical load imposed on the bucket foundation is transferred from the soil inside the bucket to the bottom of the foundation, and also to the outer surface of the skirt. For the design of a bucket foundation installed in sand, the vertical load transfer characteristics have to be clearly identified. However, the response of bucket foundations in sand subjected to a vertical load has not been investigated. In this study, we performed two-dimensional axisymmetric finite element analyses and investigated the vertical load transfer mechanism of bucket foundation installed in sand. The end bearing capacity of bucket foundation is shown to be larger than that of the shallow foundation, whereas the frictional resistance is smaller than that for a pile. The end bearing capacity of the bucket foundation is larger than the shallow foundation because the shear stress acting on the skirt pushes down and enlarges the failure surface. The skin friction is smaller than the pile because the settlement induces horizontal movement of the soil below the tip of the foundation and reduces the normal stress acting at the bottom part of the skirt. The calculated bearing capacity of the bucket foundation is larger than the sum of end bearing capacity of shallow foundation and skin friction of pile. This is because the increment of the end bearing capacity is larger than the reduction in the skin friction.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1183-1190
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• 2005

본 논문에서는 백령도 사곶해수욕장의 지반지지력 변화를 알아보고자, 평판재하시험(이하 PBT로 표시함)을 실시하였다. 시험에서 얻어진 데이터는 최대곡률법, logP-logs법, $P-{\triangle}s/{\triangle}(logt)$법을 종합적으로 분석 검토하여 결과값을 산출하였고, 시료를 채취하여 실내실험을 한 결과 통일분류법상 SP의 상태를 나타내었다. 재하시험과 실내실험의 데이터를 비교 분석한 결과, 물다짐의 상태에 따라 침하량의 차이가 2배 가까이 차이를 보였으며, 물다짐이 이루어진 곳의 침하량값이 작고, 허용지지력이 높은 것으로 산출 되었다.