• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.239-248
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• 2006

The interaction between ground water and structure is complicated behavior which cannot be easily investigated In the laboratory and monitored in the fields. In this study numerical simulation of the interactive behavior was performed using sophisticated coupled-finite element method. Hydraulic behavior of structure is modeled using solid elements with finite Permeability. Recovery of ground water table in the long-term is considered by controlling hydraulic boundary conditions. The results showed that the interaction effect is significant. Particularly non-symmetry in the lining permeability resulted in highly unbalanced pore water pressure which may cause detrimental effects on inner linings of tunnels acting as drains.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.415-424
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• 2004

This paper presents the effect of groundwater on tunneling performance. The interaction between the tunneling and groundwater was examined using a 3D stress-pore pressure coupled finite-element analysis, The results of the 3D coupled analysis were then compared with those of a total stress analysis. Examined items included pore pressures around lining and lining forces. Also examined include face displacements and ground surface movements, The results indicated that the interaction between the tunneling and ground water significantly increases the lining forces and ground deformations, and that the effect of ground water on tunneling can only be captured through a fully coupled analysis, Implementations of the findings from this study arc discussed in great detail.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 2차
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• pp.13-20
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• 2010

This paper presents the results of a numerical investigation on the ground deformation in deep excavation with emphasis on the groundwater lowering. Using the stress-pore pressure coupled analysis Consideration to the effect of ground excavation and groundwater interaction were carried out and a series of two-dimensional finite element model was employed to perform a parametric study on a wide range of soil profile and initial ground water table condition.

• Structural Engineering and Mechanics
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• 제40권6호
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• pp.829-845
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• 2011

This paper evaluates the effects of topographical and geotechnical irregularities on the dynamic response of the 2-D soil-structure systems under ground motion by coupling finite and infinite elements. A numerical procedure is employed, and a parametric study is carried out for single-faced slope topographies. It is concluded that topographic conditions may have important effects on the ground motion along the slope. The geotechnical properties of the soil will also have significantly amplified effects on the whole system motion, which cannot be neglected for design purposes. So, dynamic response of a soil-structure systems are primarily affected by surface shapes and geotechnical properties of the soil. Location of the structure is another parameter affecting the whole system response.

• Earthquakes and Structures
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• 제3권3_4호
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• pp.435-455
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• 2012

An impact on the ground surface may represent several phenomena, such as a crash of an airplane or an explosion or the passage of a train. In order to analyze and design structures and equipment to resist such a type of shocks, the response spectra for an impact on the ground must be given. We investigated the half-space motions due to impact using the finite element method. We performed extensive parametric analyses to define a suitable finite element model and arrive at displacement time histories and response spectra at varying distances from the impact point. The principal scope of our study has been to derive response spectra which: (a) provide insight and illustrate in detail the half-space response to an impact load, (b) can be readily used for the analysis of structures resting on a ground subjected to an impact and (c) are a new family of results for the impact problem and can serve as reference for future research.

• Structural Engineering and Mechanics
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• 제86권1호
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• pp.85-92
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• 2023

This article examines the seismic vulnerability of soil nail wall structures. Detailed information regarding finite element modeling has been provided. The fragility function evaluates the relationship between ground motion intensities and the probability of surpassing a specific level of damage. The use of incremental dynamic analysis (IDA) has been applied to the soil nail wall against low to severe ground motions. In the nonlinear dynamic analysis of the soil nail wall, a set of twenty seismic ground motions with varying PGA ranges are used. The numerical results demonstrate that the soil-nailed wall reaction is extremely sensitive to earthquake ground vibrations under different intensity measures (IM). In addition, the analytical fragility curve is provided for various intensity values.

• 한국터널지하공간학회 논문집
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• 제24권4호
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• pp.341-353
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• 2022

도심지에는 많은 지중 매설관이 설치되어 있으며, 이러한 지중 관로의 위치(깊이, 방향 등)은 굴착을 수행하기 전에 특정되어야 한다. 지중 매설관을 탐지하기 위해 다양한 지구물리학적인 방법을 사용할 수 있으나, 지반의 불균질성으로 인해 정확한 위치정보를 파악하는 것은 어렵다. 다양한 비파괴 탐사 방법 중 GPR (ground penetrating radar)는 고속으로 실험이 가능하며, 다른 탐사 방법에 비해 상대적으로 저렴한 탐사비용 등의 장점을 갖는다. 그러나 GPR의 탐사 데이터는 해석이 직관적이지 않아 상당한 전문적 지식이 요구된다. 최근 딥러닝을 이용한 탐사 데이터의 자동판독 기술에 대한 연구가 증가하고 있으나, 매설물의 위치를 정확히 알고 있는 탐사 데이터가 부족하여 학습모델 구축에 어려움이 있다. 이를 해결하기 위해 본 연구에서는 이러한 문제를 FDTD (finite difference time domain)수치해석을 통해 해결하고 자동탐지 학습 모델의 성능을 향상시키기 위한 기초연구를 수행하였다. 첫째, 단일유전율로 구성된 균질지반을 구성하고 해석을 수행하였다. 불균질 지반의 경우 프랙탈 기법을 이용하여 모델을 구성하고 해석을 수행하였다. 둘째, 합성곱 신경망을 이용하여 딥러닝 학습을 수행하였다. Model-A는 균질 지반 해석 데이터만 이용하여 학습을 수행하였으며, Model-B는 균질 및 불균질 지반 해석 데이터를 이용하여 학습을 수행하였다. 그 결과 Model-B가 Model-A보다 탐지성능이 우수한 것을 확인하였다. 이는 자동탐지 모델의 학습 시, 지반의 불균질성을 포함하여 학습을 수행하면 탐지 모델의 성능이 개선됨을 의미한다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.189-198
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• 2006

This paper concerns the finite element (FE) modeling approach for NATM tunneling in water bearing ground within the framework of stress-pore pressure coupled analysis. Fundamental interaction mechanism of ground and groundwater lowering was first examined and a number of influencing factors on the results of coupled FE analysis were identified. A parametric study was then conducted on the influencing factors such as soil-water characteristics, location of hydraulic boundary conditions, the way of modeling drainage flow, among others. The results indicate that the soil-water characteristics plays the most important role in the tunneling-induced settlement characteristics. Based on the results, modeling guidelines were suggested for stress-pore prssure coupled finite element modeling of NATM tunneling.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1993년도 봄 학술발표회논문집
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• pp.207-212
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• 1993

In the construction of underground structures, it is critical to accurately predict the ground deformations during excavation. In this paper, a finite element procedure for the computation of solid displacement and fluid pore pressure during incremental excavation is presented based on Biot's theory. The numerical formulation is done using the virtual work principle. The proposed procedure is applied to some example problems with different excavation rates and permeabilities.

• 한국안전학회지
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• 제7권4호
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• pp.55-61
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• 1992

An engineer designing a tunnel in an urban area should be to predict the magnitude and distribution of ground movements which are important to Investigate the potential damage to the existing structures around tunnel. The present study examines available theories and emprical equations, and tries to investigate quantativily ground movements around tunnel with tunnel progressing. Approcaches to the problem of ground movements associated with twin tunnel was and elasto - plastic finite element method. Typical section in Seoul Subway were selected in numerical study. The analysis and study was done with respect. to surface, subsurface and crown settlements with varying ground conditions, tunnel geommetry and construction conditions.