• 한국암반공학회:학술대회논문집
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• 한국암반공학회 2000년도 암반공학문제의 수치해석(Numerical Analysis in Rock Engineering Problems)
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• pp.211-222
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• 2000

대형 구조물 기초로 암반에 근입된 현장타설말뚝의 사용이 현저히 증가하고 있음에도 암반의 공학적 물성과 설계정수와의 관련이 명확히 정립되지 못한실정이다. 이에 본 연구에서는 암반근입말뚝의 거동 특성을 이론적으로 연구하고, 이를 수치적으로 모델링하기 위하여 지반-구조물 상호작용에 관련한 경계면 물성을 기존 연구 결과에 기초하여 합리적으로 산정하였다. 암반의 물성과 경계면 물성간의 관계를 이용하여 암반근입말뚝의 거동을 수치적으로 모사할 수 있으며 , 또한 현장 계측을 통해 얻은 말뚝의 하중전이 양상이 수치적으로 모사된 결과와 잘 일치함을 확인하였다.

• 터널과지하공간
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• 제10권3호
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• pp.457-468
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• 2000

대형 구조물 기초로 암반에 근입된 현장타설말뚝의 사용이 현저히 증가하고 있음에도 암반의 공학적 물성과 설계정수와의 관련이 명확히 정립되지 못한 실정이다. 이에 본 연구에서는 암반근입말뚝의 거동 특성을 이론적으로 연구하고, 이를 수치적으로 모델링하기 위하여 지반-구조물 상호작용에 관련한 경계면 물성을 기존 연구 결과에 기초하여 합리적으로 산정 하였다. 암반의 물성과 경계면 물성간의 관계를 이용하여 암반근입말뚝의 거동을 수치적으로 모사 할 수 있으며, 또한 현장 계측을 통해 얻은 말뚝의 하중전이 양상이 수치적으로 모사 된 결과와 잘 일치함을 확인하였다.

• Structural Engineering and Mechanics
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• 제38권1호
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• pp.65-79
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• 2011

Concrete hydraulic structures such as: Dams, Intake Towers, Piers and dock are usually recognized as" Vital and Special Structures" that must have sufficient safety margin at critical conditions like when earthquake occurred as same as normal servicing time. Hence, to evaluate hydrodynamic pressures generated due to seismic forces and Fluid-Structure Interaction (FSI); introduction to fluid-structure domains and interaction between them are inevitable. For this purpose, first step is exact modeling of water-structure and their interaction conditions. In this paper, the basic equation involved the water-structure-foundation interaction and the effective factors are explained briefly for concrete hydraulic structure types. The finite element modeling of two concrete gravity dams with 5 m, 150 m height, reservoir water and foundation bed rock is idealized and then the effects of fluid domain and bed rock have been investigated on modal characteristic of dams. The analytical results obtained from numerical studies and modal analysis show that the accurate modeling of dam-reservoir-foundation and their interaction considerably affects the modal periods, mode shapes and modal hydrodynamic pressure distribution. The results show that the foundation bed rock modeling increases modal periods about 80%, where reservoir modeling changes modal shapes and increases the period of all modes up to 30%. Reservoir-dam-foundation interaction increases modal period from 30% to 100% for different cases.

• Computational Structural Engineering : An International Journal
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• 제2권1호
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• pp.33-42
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• 2002

A computationally efficient stiffness design method for building structures is proposed in which dynamic soil-structure interaction based on the wave-propagation theory is taken into account. A sway-rocking shear building model with appropriate ground impedances derived from the cone models due to Meek and Wolf (1994) is used as a simplified design model. Two representative models, i.e. a structure on a homogeneous half-space ground and a structure on a soil layer on rigid rock, are considered. Super-structure stiffness satisfying a desired stiffness performance condition are determined via an inverse problem formulation for a prescribed ground-surface response spectrum. It is shown through a simple yet reasonably accurate model that the ground conditions, e.g. homogeneous half-space or soil layer on rigid rock (frequency-dependence of impedance functions), ground properties (shear wave velocity), depth of surface ground, have extensive influence on the super-structure design.

• 한국지반환경공학회 논문집
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• 제19권2호
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• pp.13-21
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• 2018

The magnitude and distribution of earth pressure on the excavation wall in jointed rock mass were examined by considering different wall permeability conditions as well as rock types and joint inclination angles. The study was numerically extended based on a physical model test (Son & Park, 2014), considering rock-structure interactions with the discrete element method, which can consider various characteristics of rock joints. This study focused on the effect of the permeability condition of excavation wall on the earth pressure in jointed rock masses under a groundwater condition, which is important but has not been studied previously. The study results showed that the earth pressure was highly influenced by wall permeability as well as rock type and joint condition. Earth pressure resulted from the study was also compared with Peck's earth pressure in soil ground, and the comparison clearly showed that the earth pressure in jointed rock mass can be greatly different from that in soil ground.

• Geomechanics and Engineering
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• 제24권5호
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• pp.471-478
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• 2021

Water damage is one of the five disasters that affect the safety of coal mine production. The erosion of rocks by water is a very important link in the process of water inrush induced by fault activation. Through the observation and experiment of fault filling samples, according to the existing rock classification standards, fault sediments are divided into breccia, dynamic metamorphic schist and mudstone. Similar materials are developed with the characteristics of particle size distribution, cementation strength and water rationality, and then relevant tests and analyses are carried out. The experimental results show that the water-rock interaction mainly reduces the compressive strength, mechanical strength, cohesion and friction Angle of similar materials, and cracks or deformations are easy to occur under uniaxial load, which may be an important process of water inrush induced by fault activation. Mechanical experiment of similar material specimen can not only save time and cost of large scale experiment, but also master the direction and method of the experiment. The research provides a new idea for the failure process of rock structure in fault activation water inrush.

• 터널과지하공간
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• 제3권1호
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• pp.96-107
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• 1993

This paper deals with the analysis of rock slope stability using the distinct element method. This method consists in analysis of the interaction of discrete block assemblage delimited by elementary joints, which permits to consider the heterogeneous, anisotropic and discontinuous features of the rock mass. In particular, we were able to show that this method, and especially the BRIG3D software, is an outstanding tool which gives informations of greatest interest in order to analyze the toppling mechanisms. We have confirmed the fundamental role of the rock mass structure with different simulations. In the case of toppling phenomena, the essential parameter is the dip of major discontinuities. It has an influence on the intensity and volume of deformations. The anisotropic and heterogeneous features of the rock mass play also an important role. It is proved by insertion of thick rock bars in the structure or varying rock block sizes in the mass. These models modified considerably the stress distribution and the deformation distribution. Finally, we have analyzed the influence of mechanical parameters such as friction angle and tangential stiffness.

• Earthquakes and Structures
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• 제10권6호
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• pp.1273-1289
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• 2016

This paper addresses the concept of lateral overstrength; the ratio of actual lateral strength to design base shear force, for both SDOF and MDOF systems considering soil structure interaction. Overstrength factors are obtained with inelastic time history analysis for SDOF systems for period range of 0.1-3.0 s, five different aspect ratios (h/r=1, 2, 3, 4, 5) and five levels of ductility (${\mu}$=2, 3, 4, 5, 6) considering soil structure interaction. Structural overstrength for MDOF systems are obtained with inelastic time history collapse analysis for sample 1, 3, 6, 9, 12 and 15 storey RC frame systems. In analyses, 64 ground motions recorded on different site conditions such as rock, stiff soil, soft soil and very soft soil are used. Also lateral overstrength ratios considering soil structure interaction are compared with those calculated for fixed-base cases.

• 한국지반환경공학회 논문집
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• 제16권2호
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• pp.33-43
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• 2015

This paper investigated the magnitude and distribution of earth pressure on the support system in jointed rock mass by considering different earth pressure coefficients, rock types and joint inclination angles. The study mainly focused on the effect of the earth pressure coefficients on the earth pressure. Based on a physical model test (Son & Park, 2014), extended studies were conducted considering rock-structure interactions based on the discrete element method, which can consider the joints characteristics of rock mass. The results showed that the earth pressure was highly influenced by the earth pressure coefficients as well as the rock type and joint inclination angles. The effects of the earth pressure coefficients increased when the rock suffered more weathering and has no joint slide. The test results were also compared with Peck's earth pressure for soil ground, and clearly showed that the earth pressure in jointed rock mass can be greatly different from that in soil ground. This study indicated the earth pressure coefficients considering the rock types and joint inclination angles are important parameters influencing the magnitude and distribution of earth pressure, which should be considered when designing the support systems in jointed rock mass.

• Structural Engineering and Mechanics
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• 제39권5호
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• pp.683-701
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• 2011

In this study, inelastic displacement ratios and ductility demands are investigated for SDOF systems with period range of 0.1-3.0 s. with elastoplastic behavior considering soil structure interaction. Earthquake motions recorded on different site conditions such as rock, stiff soil, soft soil and very soft soil are used in analyses. Soil structure interacting systems are modeled with effective period, effective damping and effective ductility values differing from fixed-base case. For inelastic time history analyses, Newmark method for step by step time integration was adapted in an in-house computer program. Results are compared with those calculated for fixed-base case. A new equation is proposed for inelastic displacement ratio of interacting system ($\tilde{C}_R$) as a function of structural period of interacting system ($\tilde{T}$), strength reduction factor (R) and period lengthening ratio ($\tilde{T}/T$). The proposed equation for $\tilde{C}_R$ which takes the soil-structure interaction into account should be useful in estimating the inelastic deformation of existing structures with known lateral strength.