• Computational Structural Engineering
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• v.8 no.3
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• pp.11-21
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• 1995

3차원 대규모 지하구조물의 동적응답을 결정하기 위한 일반적인 수치해석이 제안되었다. 지반과 구조물을 해석하기 위하여 Laplace 변환을 적용한 경계요소법을 설명하였고, 지반-구조물계에 작용하는 외부 동적하중과 지진파를 고려할 수 있도록 공식화하였다. 동적교란이 전파되는 경우에 시간영역의 응답을 얻기 위하여는 구해진 변화된 해를 수치적인 Laplce 역변환을 수행하여야 하지만 동적교란이 조화적인 경우에는 응답이 주파수 영역으로부터 직접 얻어지며, 역변환이 필요하지 않다. 이 방법의 특징은 높은 정확도와 효율성이며, 지반-구조물계에 대하여 초기조건 및 점탄성 재료의 거동을 쉽게 고려할 수 있다는 것이다. 그러므로 이 방법은 다양한 지하구조물의 동적거동과 지진에 대한 취약함을 연구하기 위한 적절한 도구로 사용되어 질 수 있다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.2
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• pp.205-217
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• 2007

The behavior characteristics of underground structures are reported as they are not affected by their dynamic characteristics such as surface structures, but by dynamic characteristics of soil and rock surrounding the underground structures. Therefore, dynamic behavior of surrounding soil and rock dominates the dynamic behavior of the underground structure. The purpose of this paper is to analyze the dynamic response (longitudinal deformation and ovaling deformation) of the underground structure under earthquake loading. The dynamic responses of the underground structures were evaluated with varying earthquake conditions, soil conditions, and structural conditions using conventional closed-form solution of seismic behavior of underground structure. In addition, shaking table tests were conducted to simulate the earthquake loading and the dynamic behavior of the model was analyzed.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.2
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• pp.163-174
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• 2009

The large underground structure under earthquake is affected more by soil dynamic characteristic and volume of structure than by structural dynamic characteristic itself. Therefore, it is the purpose of research that the aseismic analysis for caverns including various aseismic analysis factors (rock quality-Q value, soil dynamic characteristic, shape ratio $&$ volume, underground structural dynamic characteristic, and aseismic level) are applied by using the numerical analysis program (SAUS; seismic analysis of underground structures). The result of research is stated that maximum strain, maximum moment, and maximum shear are not sensitive with respect to shape ratio. However those values are sensitive with respect to Q value, volume of underground structure and aseismic level. Based on the results of this research, the assessment for the influence factors of aseismic analysis for large underground structure could be possible.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.4
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• pp.671-686
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• 2018

Recently, earthquakes have occurred near Gyeongju and Pohang and the social demands are thus being increased for seismic analysis of tall buildings and their adjacent underground structure in big cities. Since most of the previous seismic analysis studies considered a tall building and an adjacent underground structure separately, however, they lack the analysis on dynamic mutual behavior between two structures. Therefore, in this study, a dynamic analysis with a full soil-structure interaction was performed for a complex underground facility with a tall building and an adjacent underground structure constructed on the bedrock with a surface layer. To improve the reliability, in particular, a pseudo-static analysis was performed and compared with the dynamic analysis results. It is comprehensively concluded that the analysis of adjacent underground structures being considered is more conservative than that of not considered.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.4
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• pp.59-68
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• 1997

In analysis of underground structures, the effects of artificial boundary conditions are considered as one of the major reasons for differences from experimental results. These phenomena can be overcome by using the boundary elements which satisfy the multi-layered half space conditions. The fundamental solutions of multi-layered half-space for boundary element method is formulated satisfying the transmission and reflection of waves at each layer interface and radiation conditions at bottom layer. The governing equations can be obtained from the displacements at each layer which are expressed in terms of harmonic functions. All types of waves can be included using the complete response from semi-infinite integrals with respect to horizontal wavenumbers using expansion of Fourier series and Hankel transformation. Two dimensional Green's functions are derived from cylindrical Navier equations and potentials performing infinite integration in y-direction. In this case, it is effective to transform into two dimensional problem using semi-analytical integration and sinusoidal Bessel function. Some verifications are given to show the accuracy and efficiency of the developed method, and numerical examples to demonstrate the dynamic behavior of underground with various properties.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.3
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• pp.391-399
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• 2001

Three-dimensional dynamic analysis of underground openings subjected to explosive loadings considering the effects of water saturation is carried out in this study. The surrounding rock mass is assumed to be the limestone with 13.5% of porosity. Two calculations are compared using as identical explosive charge; the first in dry rock of 13.5% porosity, the second in the identical rock, but in a fully saturated condition. It is shown that velocity, displacement, and stress time histories are higher in saturated rock than those in dry rock through numerical studies. It is also shown that underground openings in saturated rock masses could be significantly more vulnerable to the potential damages associated with shear failure than those in dry medium.

• Computational Structural Engineering
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• v.2 no.2
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• pp.53-62
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• 1989

In recent times, the subterranean caverns for storing crude oils and oil products are increasingly needed. The elasto-VIScoplastic DYNamic finite element analysis program(VISDYN) has been developed in order to investigate dynamic responses of the storage cavity. And validity of the program is studied through a numerical example. Mohr-Coulomb yield criterion is adopted and associated flow rule is assumed. Geometrically nonlinear behaviour is taken into account using a total Lagrangian formulation. In dynamic deformation reponses, the difference between the steady state displacements and the unsteady state ones by the static analysis can be neglected.

• Computational Structural Engineering
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• v.4 no.4
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• pp.117-124
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• 1991

In order to predict properly the effects of ground motion associated with earthquakes on underground radioactive waste disposal facilities, an understanding of the structural behavior of an underground opening in discontinuous rock masses subjected to dynamic loadings is essential. This paper includes literature review on computational models for discontinuous rock masses and on mathematical models for the structural analysis of underground opening. Then, structural analyses of underground openings using the distinct element computer program written for the static and dynamic analysis of discontinuous rock masses have been performed.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.23-38
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• 2018

Up to now, most of studies on seismic analysis have been limited to analyze buildings and underground structures individually so that the interaction between them could not be analyzed effectively. Thus, in this study, a dynamic analysis was conducted for soil-structure interaction with a complex underground facility composed of a building and an adjacent underground structure constructed on a surface soil and the bed rock ground conditions. Seismic stability was analyzed based on interstory drift ratio and bending stress of structure members. As a result, an underground structure has more effect on a high-rise building than a low-rise building. However the above structures were proved to be favorable for seismic stability. On the other hand, tensile bending stresses exceeded the allowable value at the underground part of the building and the adjacent underground structure so that it turned out that the underground part could be weaker than the above part. Therefore, it is inferred that above and underground structures should be analyzed simultaneously for better prediction of their interaction behavior during seismic analyses because there exist various structures around buildings in big cities.

• Journal of Korean Tunnelling and Underground Space Association
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• v.7 no.3
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• pp.249-257
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• 2005

There are basically two methods for the seismic design of underground structures ; analytical or pseudo-static, and dynamical method. In pseudo-static analysis approach, the ground deformations are imposed as a static load and soil-structure interaction does not include dynamic or wave propagation effects. However the behavior of soil structure interaction is nonlinear, it needs to consider nonlinear soil-structure interaction effects. In this study simplified seismic analysis method to consider soil-structure interaction by iterative procedure is proposed and the results are compared and analyzed by a finite difference computer program.