• 산업기술연구
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• 제22권B호
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• pp.211-218
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• 2002

The paper is to show the behavior of composit ground which is installed with sheet pile in soft soil improved by sand compaction pile. The results of load-settlement relationship, earth pressure, stress concentration characteristics, and final water content were obtained by centrifuge model test. Two cases of tests, installation of sheet pile on the corner and both side of the loading plate for the improved SCP ground which was designed twice of the footing width, were performed for the tests under the vertical and horizontal loading and both side of corner. Finite element program(CRISP) for sand compaction pile using elasto-plastic model and numerical analysis for soft soil using modified cam-clay constitutive equation were compared and analized with the results of model tests. The result of analysis show the increased bearing capacity of soil after, SCP and sheet pile was installed.

• Structural Engineering and Mechanics
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• 제50권6호
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• pp.741-754
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• 2014

The conventional PHC pile-footing connection is the weak part because the surface area and stiffness are sharply changed. The Composite PHC pile reinforced with the transverse shear reinforcing bars and infilled-concrete, hereafter ICP pile, has been developed for improving the flexural and shear performance. This paper investigates the cyclic behavior and performance of the ICP pile-footing connection. To investigate the behavior of the connection, one PHC and two ICP specimens were manufactured and then a series of cyclic loading tests were performed. From the test results, it was found that the ICP pile-footing connection exhibited higher cyclic behavior and connection performance compared to the conventional PHC pile-footing connection in terms of ductility ratio, stiffness degradation and energy dissipation capacity.

• Geomechanics and Engineering
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• 제33권4호
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• pp.415-425
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• 2023

Pile-supported wharves, port structures that support the upper deck, are installed on sloping ground. The sloping ground should be covered with a rubble mound or artificial blocks to protect the interior material from erosion caused by wave force. The behavior of the pile may vary during an earthquake if a rubble mound is installed on the slope. However, studies evaluating the effect of rubble mound on the pile during an earthquake are limited. Here, we performed dynamic centrifuge model tests to evaluate the dynamic behavior of piles installed in a slope reinforced with rubble mound. In the structure, some sections (single-pile, 2×2 group-pile) were selected for the experiment. The moment of the group-pile decreased by up to 26% upon installation of the rubble mound, whereas the moment of the single-pile increased by up to 41%, thus demonstrating conflicting results.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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• pp.127-134
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• 2001

In this paper flexure-compression characteristics of concrete filled glass fiber reinforced composite pile was studied. Confinement model of composite pile was derived from experimental data. Also numerical method to find P-M diagram of composite pile was developed. The flexure-compression test results were compared with analytical P-M diagram and it is demonstrated that they agree well each other. Utilizing these results, pilot composite pile was designed and fabricated.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.389-396
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• 2002

Engineers should be careful in the design of bonding piles into pile caps because they are weak points in the pile foundation. Therefore in this study, the mechanism of bonding piles into pile caps was explained, and the design method of the composite bonding method was proposed. And the proposed design method was verified in comparison with the result of the full scale test. Also, the characteristic for the bearing capacity and the mechanism of compressive load of bonding method were analyzed.

• 한국지반공학회논문집
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• 제35권9호
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• pp.29-36
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• 2019

직경 500mm 및 직경 600mm PHC말뚝 A종의 파괴 압축하중($P_n$)은 각각 7.7MN 및 10.6MN으로 계산할 수 있었다. 직경 500mm 및 직경 600mm 매입 PHC말뚝 A종에 대한 압축정재하시험 시 말뚝 두부에 재하된 최대 압축하중은 6.9MN 및 8.8MN으로 측정할 수 있었으며 따라서 이 측정하중은 각각 $P_n$의 90% 및 83% 수준이었다. 직경 500mm 및 직경 600mm PHC말뚝 A종의 장기허용압축하중($P_a$)은 각각 1.7MN 및 2.3MN이었다. 모든 사례 매입 PHC말뚝의 양방향재하시험 자료로부터 계산된 지반의 허용지지력은 국내 현행 설계에서 사용하고 있는 극한지지력 산정공식으로 계산한 지반의 허용지지력보다 높은 수준으로 계산되었다. 따라서 매입 PHC말뚝의 설계에서 사용하는 극한지지력 산정공식은 매입 PHC말뚝의 실제 지지력 거동을 모사할 수 있도록 개선하여야 할 것으로 판단되었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.211-218
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• 2004

The objective of this study is to enhance the ultimate bearing capacity of piles embedded in marine clay by electrokinetic(EK). The focus of improvement is at interlace between soil and pile. A series laboratory test was performed in EK cell. In each of test, the pile in the centre as anode is surrounded by cathode and it was installed in the vicinity of pile with triangular layout. The pile was made by stainless and embedded with 30cm of depth. Afterward, the DC voltage was applied to electrode over period of time. It caused flowing water from anode to cathode, thus the soil in the center of box has higher bearing capacity value than in the side of box has. It is shown by increasing of un-drained shear strength(Cu) near the pile and also ultimate bearing capacity of pile increase after EK treatment. In the future work, the continuous of this study is finding the effective DC voltage and makes EK treatment more applicable in the field.

• 한국지반공학회지:지반
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• 제8권2호
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• pp.21-30
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• 1992

말뚝의 주면마찰력은 전체 지지력중 상당한 하중을 지지할 수 있으나 실제 설계시에는 무시되는 경우가 많이 있다. 주면마찰력을 설계에 반영할 경우에도 계산결과의 신뢰도는 매우 낮은 것이 현실이다. 국내의 사정은, 설계 자료로 활용할 수 있는 것은 표준관입시험 결과뿐인 경우가 대부분으로 빈곤하며 특히 국내에 많은 화강암, 편마암의 풍화잔류토에 관해서는 설계자료가 극히 희박해 외국에 비해 열악하다. 최근에 국내에서 개발된 간편한 말뚝재하시험(simple pile loading test: SPLT)의 사용은 선단지지력과 주면마찰력의 별도 측정이 가능하도록 하였다. 본 연구에서는 풍화잔류토 지반에서의 SPLT 결과를 분석하여 N값에 의한 새로운 설계관계식을 제안하였다.

• 한국산학기술학회논문지
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• 제8권1호
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• pp.103-109
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• 2007

본 논문에서는 시스템 파라미터의 변동이나 모델의 불확실성 및 외부 외란 등에 강인한 외란 관측기에 기초로 한 강인 제어기의 설계를 제안한다. 제어기는 두 개 루프의 구조를 갖는 모델기반 보상기와 궤환 제어기 구조로 구성되어 있다. 내부 루프 보상기는 내외부의 외란을 제거하고, 외부 루프 궤환 제어기는 주어진 사양을 만족하도록 하는 역할을 수행한다. 결과적으로, 제안한 강인 제어기를 이용함으로써 외란에 대해 시스템을 안정화시킬 수 있으며, 제어 성능을 향상시킬 수 있음을 보인다.

• Earthquakes and Structures
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• 제20권1호
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• pp.87-96
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• 2021

Ground motions recorded in near-fault sites, where the rupture propagates toward the site, are significantly different from those observed in far-fault regions. In this research, finite element modeling is used to investigate the effect of pile cap stiffness on the seismic response of soil-pile-structure systems under near-fault ground motions. The Von Wolffersdorff hypoplastic model with the intergranular strain concept is applied for modeling of granular soil (sand) and the behavior of structure is considered to be non-linear. Eight fault-normal near-field ground motion records, recorded on rock, are applied to the model. The numerical method developed is verified by comparing the results with an experimental test (shaking table test) for a soil-pile-structure system. The results, obtained from finite element modeling under near-fault ground motions, show that when the value of cap stiffness increases, the drift ratio of the structure decreases, whereas the pile relative displacement increases. Also, the residual deformations in the piles are due to the non-linear behavior of soil around the piles.