• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1541-1549
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• 2013

This study investigates the response of structures to tunnelling-induced ground movements in sand ground, varying tunnel excavation condition (tunnel depth and diameter), tunnel construction condition (ground loss), ground condition (loose sand and dense sand). Four-story block-bearing structures have been used because the structueres can easily be characterized of the extent of dmages with crack size and distribution. Numerical parametric studies have been used to investigae of the response of structures to varying tunnelling conditions. Numerical analysis has been conducted using Discrete Element Method (DEM) to have real cracks when the shear and tensile stress exceed the maximum shear and tensile strength. The results of structure responses from various parametric studies have been integrated to consider tunnel excavation condition, tunnel construction condition, and ground condition and provided as a relationship chart. Using the chart, the response of structures to tunnelling can easily be evaluated in practice in sand ground.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.175-183
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• 2014

This study investigates the response of structures to tunnelling-induced ground movements in clay ground, varying tunnel excavation condition (tunnel depth and diameter), tunnel construction condition (ground loss), and tunnel ground condition (soft clay and stiff clay). Four-story block-bearing structures have been used because the structures can easily be characterized of the extent of damages with crack size and distribution. Numerical parametric studies have been used to investigate of the response of structures to varying tunnelling conditions. Numerical analysis has been conducted using Discrete Element Method (DEM) to have real cracks when the shear and tensile stress exceed the maximum shear and tensile strength. The results of structure responses from various parametric studies have been integrated to consider tunnel excavation condition, tunnel construction condition, and tunnel ground condition and provide a relationship chart among them. Using the chart, the response of structures to tunnelling can easily be evaluated in practice in clay ground.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1C
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• pp.53-63
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• 2011

This paper investigates the effects of tunnelling-induced ground movements on nearby structures, considering soil-structure interactions of different ground (loose sand, dense sand, soft clay, stiff clay) and construction conditions (ground loss). The response of four-story block structures, which are subjected to tunnelling-induced ground movements, has been investigated in different ground and construction conditions (ground loss) using numerical analysis. The structures for numerical analysis has been modelled using Discrete Element Method (DEM) to have real cracks when the shear and tensile stress exceed the maximum shear and tensile strength. The response of four-story block structures has been investigated with a ground movement magnitude and compared in terms of ground and construction conditions (ground loss) considering the magnitude of deformations and cracks in structures. In addition, the damage levels, which are possibly induced in structures, has been provided in terms of ground and construction conditions (ground loss) using the state of strain damage estimation criterion (Son and Cording, 2005). The results of this study will provide a background for better understandings for controlling and minimizing building damage on nearby structures due to tunnelling-induced ground movements.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6C
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• pp.255-263
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• 2010

This paper investigates the effects of tunnelling-induced ground movements on nearby structures, considering soil-structure interactions of different construction (ground loss) and soil characteristics. The response of four-story block structures, which are subjected to tunnelling-induced ground movements, has been investigated in different construction (ground loss) and soil conditions using numerical analysis. The structures for numerical analysis has been modelled using Discrete Element Method (DEM) to have real cracks when the shear and tensile stress exceed the maximum shear and tensile strength. The response of four-story block structures has been investigated with a ground movement magnitude and compared in terms of construction (ground loss) and soil conditions considering the magnitude of deformations and cracks in structures. In addition, the damage levels, which are possibly induced in structures, has been provided in terms of construction (ground loss) and soil conditions using the state of strain damage estimation criterion (Son and Cording, 2005). The results of this study will provide a background for better understandings for controlling and minimizing building damage on nearby structures due to tunnelling-induced ground movements.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.734-742
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• 2016

Global warming and the depletion of fossil fuels have been caused by decades of reckless development. Wind energy is one form of renewable energy and is considered a future energy source. The wind tower is designed with a fundamental frequency in the soft-stiff design between the 1P and 3P range to avoid resonance. Usually, to perform natural frequency analysis of a wind tower, the boundary condition is set to the Fixed-End, and soil-pile interaction is not considered. In this study, consideration of the effect of soil-pile interaction on the wind tower was included and the difference in the natural frequency was studied. The fixed boundary condition was not affected by the soil condition and depth of the pile and the coupled spring boundary condition was unaffected by the depth of pile but affected by the depth of the pile, and the Winkler spring boundary condition is affected by both the soil condition and the depth of the pile. Therefore, the coupled spring boundary condition should be used in shallow depth soil conditions because the soil condition does not take the shallow depth soil into consideration.

• Journal of the Korean Geotechnical Society
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• v.16 no.6
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• pp.105-115
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• 2000

본 연구는 현실에 부합하는 연약지반의 압밀거동을 예측하기 위한 연구로서, 일단 3차원 배수 조건하에서 지반의 자중 및 압축성과 투수성의 비선형적 성질이 고려된 비선형 압밀모델을 구성하였다. 또한 연직 배수재의 시공과정에서 발생할수 있는 지반의 교란현상 및 다양한 이질층의 구성, 점증적인 하중재하 조건, 연직배수재의 부분관입 조건에 대한 고려가 가능하도록 비선형 압밀모델을 수정, 보완하였다. 이상의 연구결과를 바탕으로 유한차분방법에 의한 수치해석을 실시하였고 최종적으로 각종 희귀분석과정을 도입한 3차원 비선형 압밀해석 프로그램을 개발하였다. Ska-Edeby의 시험시공 사례를 통한 개발 프로그램의 검증을 실시하였는데, 시험시공 사례의 경우, 현장에서 측정한 깊이별 침하량 및 간극수압 결과를 개발 프로그램에 의한 예측결과와 비교, 분석하였다. 또한 개발 프로그램을 이용하여 다층지반 해석과 관련된 기존 해석방법의 문제점 및 지반의 교란효과와 연직배수재의 부분관입조건, 점증적인 하중재하 조건등이 지반의 압밀거동에 미치는 영향에 대해 살펴보았다.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.1
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• pp.7-11
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• 2002

By focusing on the resonant vibration mode of soil-underground structure system, this paper obtained dynamic soil stiffness and easy sliding conditions at the interface between soil and underground structure. Multi-step method is employed to isolate two primary causes of soil-structure interaction. Mohr-Coulomb criterion is used to determine the threshold level of the sliding. To find out the conditions the interface slides easily, parametric studies are performed about the factors governing sliding, which are the size and location of underground structures, ground condition, the configuration of surface deposit and interface friction coefficients.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5C
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• pp.239-250
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• 2009

Tunnelling-induced settlements and lateral ground movements have been investigated by numerical parametric studies considering ground condition, excavation characteristics, and ground layers. Before the numerical study the existing methods of ground movement estimation have been collected and analysed to have some information of ground movements and to improve them providing a fundamental material for the numerical study. Numerical model simulation has been performed of a physical model test of tunnel excavation in which the ground movements were measured reliably and the results have been used to determine the numerical approach and the appropriate soil constitutive mode. With this procedure done, the results of numerical parametric studies have been put together to analyze and understand tunnelling-induced settlements and lateral ground movements.

• The Journal of Engineering Geology
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• v.27 no.2
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• pp.133-141
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• 2017

In this study, filter conditions by difference in grading between core material and filter material used for dam construction was applied as evaluation condition for surrounding ground conditions near excavation site in a bid to identify the risk of land subsidence resulting from the erosion of soil particles. To that end, filter conditions proposed for the test was evaluated and the risk of land subsidence depending on grain size conditions was also evaluated using the filter conditions developed by COE. Consequently, evaluation diagram that can be used to determine the risk of land subsidence using grain size conditions obtained from ground investigation data was developed, which is expected to help evaluate the possibility of land subsidence depending on changes to the stratum. To simulate the particle flow process, PFC3D program was used. It's not only intended to determine the land subsidence pattern caused by falling ground water level but also predict and evaluate the land subsidence caused by soil erosion using grain size condition which can be verified by numerical analysis approach.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.214-214
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• 2011

최근 국내 연안역에는 관광의 활성화 등의 목적으로 잔교가 많이 가설되고 있다. 그러나 잔교의 설계에 대한 규정이 없어 현재는 항만 및 어항설계기준을 준용하여 설계하고 있는 실정이며, 또한 지역적 특성을 반영하지 못하고 건설되어 과다한 단면을 사용하는 경우가 많고, 경제성이나 경관성을 갖추지 못한 경우가 많은 실정이다. 본 연구에서는 합리적인 잔교용 설계기준을 마련하기 위한 기초적인 연구로써 지반조건을 고려한 잔교의 거동특성을 분석하고자 하였다. 이를 위하여 해석모델을 개발하고, 다양한 해석조건에 대한 해석을 수행하여 그 특성을 정리하고자 하였다. 이를 통하여 잔교의 합리적인 구조시스템을 개발하고, 설계기준을 정리하는데 이바지 하고자 한다. 이 연구에서는 서해안의 연약지반을 고려하기 위해 지반스프링을 이용한 해석모델을 개발하고, 다양한 해석조건에 대한 해석을 수행하여 그 특성을 파악하고자 하였다. 조립식 잔교는 Capbeam, Wood Deck, ㄱ형강, Pile로 네 가지의 구성으로 이루어지고, 이 네 가지 요소의 재료는 강재로 사용하였으며, 하중에 대해서는 항만 및 어항설계기준을 준용하여 군중하중 $5kN/m^2$, 월파력 $20.1kN/m^2$을 사용하였고, 풍하중은 도로교 설계기준을 이용하여 산정한 $3.309kN/m^2$을 사용하였다. 재하하중 및 하중에 대한 최적단면에 대한 연구를 활용하여 본 연구에서는 지반조건의 영향, Capbeam과 Pile의 크기변화, 사항 등의 영향을 고려하였을 때 각 구성요소에서 발생하는 단면력의 변화와 축력, 접합부 모멘트 등의 외력과 내력을 정리하여 잔교의 거동특성을 파악하고자 하였다. 다양한 변수해석을 수행하기 위하여 지반조건을 고려한 2D 해석모델을 개발하였으며, 본 연구에서 고려한 군중하중, 풍하중, 월파력의 설계하중 중에서는 월파력이 지배적인 것을 알 수 있었다. Pier의 지름이 증가 하면 작용하는 월파력이 커지고 따라서 단면력이 증가하는 것을 알 수 있었다. 그러므로 합리적인 Pier의 크기 결정이 경제적이고 경관이 우수한 잔교 건설에 중요 요인임을 알 수 있다. 본 연구는 잔교의 설계기준 정립에 기초자료로 활용할 수 있을 것으로 판단되나, 보다 합리적인 잔교의 설계와 시공을 위해서는 지속적인 연구가 필요한 것으로 판단된다.