• Journal of the Korean GEO-environmental Society
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• v.13 no.6
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• pp.73-81
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• 2012

Safety issue for offshore wind-turbine foundation becomes a crucial factor as offshore wind turbines have been scaled up. Correspondingly, there is a demand to understand the effect of soil-structure interaction on to system behavior in geotechnical engineering point of view. The p-y curve method researched in past few decades is one of the most appropriate methodology to analyze the problem. In this study, recently proposed p-y curve models for various rocks are calibrated to analyze the engineering characteristics of seabed of Jeju Island where it is known to be most suitable area for offshore wind energy farm. Step by step calibration process for p-y models is presented. Analysis results show that subgrade reaction generally increases as closer to seabed. It is also shown that the behavioral characteristics of foundation reflect well rock properties in terms of resultant moment, shear force, etc.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2015.11a
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• pp.168-169
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• 2015

최근 위험물질에 의한 폭발 및 테러의 위험성 증가로 인하여 사회간접자본 시설물인 댐/보, 원자력 발전소, 병원 구조물과 같은 주요 시설물의 폭발 안전성 평가 연구가 이슈화 되고 있어, 본 연구에서는 가스폭발에 의한 다기능 보 구조물의 거동을 평가하고 안전성을 분석 하고 자 한다. 본 연구에서 폭발 해석에 필요한 하중 조건 산정은 PHAST 프로그램을 사용하여 주변 온도 및 공기 특성 등을 고려한 약 5톤의 가스 폭발 조건을 구축 하였다. 또한 다기능 보 구조물의 거동 분석을 위해 구조물-지반 상호 작용을 고려한 2차원 유한 요소 모델을 구축하여 폭발에 의한 구조물 거동을 평가 하였다. 다기능 보 구조물의 수치해석 결과 보 구체와 Stilling Basin구조물 사이의 연결부에 응력집중 현상이 발생하는 것으로 평가 되었다.

• Journal of the Korean GEO-environmental Society
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• v.2 no.4
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• pp.15-27
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• 2001

This paper proposes the force equations(thrust, moment) of corrugated steel culverts through the finite element method. The conditions for maximum thrust and maximum moment are determined from the analysis of soil-structure interaction during the three construction stages, such as backfill to the crown, backfill to the soil cover, and live loads. The proposed form of thrust and moment equations are deduced from the analysis of behaviour and the application of Castigliano's second theorem for the semi-arch structure. Finally, the coefficients used in the proposed equations are determined from a large number of analysis for the various geometries and the soil-structure relative stiffness under the conditions of maximum thrust and maximum moment.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.999-1004
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• 1995

본 논문에서는 현재 수행 중인 Hualien 대형내진모델시험 프로젝트의 연구 과제 중의 강제 진동 해석 및 지진 응답 해석을 수행하기 위계서 Hyperelement를 사용한 지반-구조물 상호작용 해석에 대한 절차 및 방법을 연구하였다. Hualien 대형내진모델시험에서 이미 수행된 뒷채움 후 강제 진동 시험의 예 측 및 예측후 해석을 수행하였고, 지진 응답 해석을 위해서는 Hualien부지에서의 자유장해석을 통하여 입력 지반 운동을 결정하여 구조물에서의 지진 응답을 구하였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.3
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• pp.155-164
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• 2019

In this study, the soil-structure interaction(SSI) effect on the seismic response of LNG storage tanks was investigated according to the type of foundation. For this purpose, a typical of LNG storage tank with a diameter of 71m, which is constructed on a 30m thick clay layer over bedrock was selected, and nonlinearity of the soil was taken into account by the equivalent linearization method. Four different types of foundations including shallow foundation, piled raft foundation, and pile foundations(surface and floating types) were considered. In addition, the effect of soil compaction in group piles on seismic response of the tank was investigated. The KIESSI-3D, which is a SSI analysis package in the frequency domain, was used for the SSI analysis. Stresses in the outer tank, and base shear and overturning moment in the inner tank were calculated. From the comparisons, the following conclusions could be made: (1) Conventional fixed base seismic responses of outer tank and inner tank can be much larger than those of considering the SSI effect; (2) The influence of SSI on the dynamic response of the inner tank and the outer tank depends on the foundation types; and (3) Change in the seismic response of the structure by soil compaction in the piled raft foundation is about 10% and its effect is not negligible in the seismic design of the structure.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.4
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• pp.245-253
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• 2020

In this study, natural frequencies are compared using several pile-soil interaction (PSI) models to evaluate the effects of each model on resonance safety checks for a monopile type of wind turbine structure. Base spring, distributed spring, and three-dimensional brick-shell models represented the PSIs in the finite element model. To analyze the effects of the PSI models on a natural frequency, after a stiffness matrix calculation and Winkler-based beam model for base spring and distributed spring models were presented, respectively; natural frequencies from these models were investigated for monopiles with different geometries and soil properties. These results were compared with those from the brick-shell model. The results show that differences in the first natural frequency of the monopiles from each model are small when the small diameter of monopile penetrates hard soil and rock, while the distributed spring model can over-estimate the natural frequency for large monopiles installed in weak soil. Thus, an appropriate PSI model for natural frequency analyses should be adopted by considering soil conditions and structure scale.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.6
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• pp.29-35
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• 2001

The soil-structure interaction(SSI) analysis is essential to soil site where shear wave velocity is less than 1,050 m/sec and soil nonlinear characteristics for this kind of soil site have to be considered in SSI analysis. In order to consider soil nonlinear characteristics in the SSI analysis, simple and reliable soil nonlinear evaluation technique with seismic recorded data at downhole array is proposed in this study. The SSI analysis is carried out in order to prove the reliability of the proposed evaluation technique with Hualien large scale seismic test(HLSST) site in Taiwan. The analytical result are compared with Hualien earthquake recorded data and the analytical results with SHAKE program which is prevailed at present. As a result, the proposed evaluation technique shows a good agreement with both the Hualien earthquake recorded data and the analytical result with SHAKE program and the reliability and usefulness are confirmed.

• Journal of the Korean GEO-environmental Society
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• v.15 no.9
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• pp.47-58
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• 2014

This study explores methods for modeling the foundation-seabed interaction needed for the load analysis of an offshore wind energy system. It comprises the comparison study of foundation design load analyses for NREL 5 MW turbine according to various soil-foundation interaction models by conducting the load analysis with GH-Bladed, analysis software for offshore wind energy systems. Furthermore, the results of the aforementioned load analysis were applied to foundation analysis software called L-Pile to conduct a safety review of the foundation cross-section design. Differences in the cross-section of a monopile foundation were observed based on the results of the fixed model, winkler spring and coupled spring models, and the analysis of design load cases, including DLC 1.3, DLC 6.1a, and DLC 6.2a. Consequently, under all design load conditions, the diameter and thickness of the monopile foundation cross-section were found to be 7 m and 80 mm, respectively, using the fixed and coupled spring models; the results of the analysis conducted using the winkler spring model showed that the diameter and thickness of the monopile foundation cross-section were 5 m and 60 mm, respectively. The study found that the soil-foundation interaction modeling method had a significant impact on the load analysis results, which determined the cross-section of a foundation. Based on this study, it is anticipated that designing an offshore wind energy system foundation taking the above impact into account would reduce the possibility of a conservative or unconservative design of the foundation.

• Journal of the Korean Society for Railway
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• v.7 no.4
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• pp.32-36
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• 2004

• Journal of the Earthquake Engineering Society of Korea
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• v.16 no.3
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• pp.13-22
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• 2012

Even with its significant influence on the dynamic analysis and foundation design of structures, sometimes the soil-structure interaction has been ignored during the design process. One of the reasons is due to the fact that the modeling procedures are too complicated to meet the requirements in practice. In this study, using the Cali(IT)2 building in California with high and frequent seismic activities, the analysis differences for different boundary conditions are reviewed. The Beam on Nonlinear Winkler Foundation Model, one of the foundation modeling methods, is modified for easy use by the Linear Matrix Inequalities Model Reduction Technique. The product of the proposed process is applied to create the Finite Element Model. The results show fairly good agreement with the real data acquired from the Cal(IT)2 building.