• Geophysics and Geophysical Exploration
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• v.13 no.2
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• pp.159-168
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• 2010

Recent trend in petroleum/gas exploration is an application of 3D seismic exploration technique. Unlike the conventional 2D seismic data processing, 3D seismic data processing is considered as the one which requires expensive commercial software systems and high performance computer. This paper propose a practical 3D seismic processing methodology on a personal computer using public domain software such as SU, SEPlib, and SEPlib3D. The applicability of the proposed method has been demonstrated by successful application to a well known realistic 3D synthetic data, SEG/EAGE 3D salt model data.

• Tunnel and Underground Space
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• v.18 no.4
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• pp.263-271
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• 2008

3D seismic tomography technique was assessed for applicability of developed 3D tomography algorithm based on Fresnel volume in the dam-planned area. Reconstructed 3D tomogram based on Fresnel volume and Fast Marching Method(FMM) reveals similar velocity structure to the other geotechnical survey results. With the correlation analysis between RMR data and seismic velocity information, it could provide reliable information of rock mass rate. The applicability of 3D seismic tomography was verified in this study. It would be expected to apply 3D tomography with new developed first arrival calculation and inversion algorithm to the engineering field economically.

• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.1109-1114
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• 2022

The SMART (System-integrated Modular Advanced ReacTor) is an integral-type small modular reactor developed by KAERI (Korea Atomic Energy Research Institute). This paper discusses the feasibility and applicability of a 3D-based equivalent model using dynamic condensation method for seismic analysis of a SMART control rod drive mechanism. The equivalent model is utilized for complicated seismic analysis during the design of the SMART. While the 1D-based beam-mass equivalent model is widely used in the nuclear industry for its calculation efficiency, the 3D-based equivalent model is suggested for the seismic analysis of SMART to enhance the analysis accuracy of the 1D-based equivalent model while maintaining its analysis efficiency. To verify the suggested model, acceleration response spectra from seismic analysis based on the 3D-based equivalent model are compared to those from the 1D-based beam-mass equivalent model and experiments. The accuracy and efficiency of the dynamic condensation method are investigated by comparison to analysis results based on the conventional modeling methodology used for seismic analysis.

• 한국지구물리탐사학회:학술대회논문집
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• 2009.05a
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• pp.35-45
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• 2009

Reservoir Characterization (RC) using 3-D seismic attributes analysis can provide properties of the oil sand reservoirs, beyond seismic resolution. For example, distributions and temporal bed thicknesses of reservoirs could be characterized by Spectral Decomposition (SD) and additional seismic attributes such as wavelet classification. To extract physical properties of the reservoirs, we applied 3-D seismic attributes analysis to the oil sand reservoirs in McMurray formation, in BlackGold Oilsands Lease, Alberta Canada. Because of high viscosity of the bitumen, Enhanced Oil Recovery (EOR) technology will be necessarily applied to produce the bitumen in a steam chamber generated by Steam Assisted Gravity Drainage (SAGD). To optimize the application of SAGD, it is critical to identify the distributions and thicknesses of the channel sand reservoirs and shale barriers in the promising areas. By 3-D seismic attributes analysis, we could understand the expected paleo-channel and characteristics of the reservoirs. However, further seismic analysis (e.g., elastic impedance inversion and AVO inversion) as well as geological interpretations are still required to improve the resolution and quality of RC.

• Geophysics and Geophysical Exploration
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• v.4 no.3
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• pp.80-83
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• 2001

Four seismic reflection horizons in 3-D seismic data, coherence derived from the seismic data, and 38 well logs from the Boonsville Gas Filed in Texas were tried to be integrated and visualized in 3 dimensions. Time surface was constructed from pick times of the reflection horizons. Average velocities to each horizon at 38 well locations were calculated based on depth markers from the well logs and time picks from the 3-D seismic data. The time surface was transformed to depth surface through velocity interpolation. Coherence was calculated on the 3-D seismic data by semblance method. Spatial distribution of the coherence is captured easily in 3-D visualization. Comparing to a time-slice of seismic data, distinctive stratigraphic features could be correctly recognized on the 3-D visualization.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.585-592
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• 2000

Primary purpose of the system developed in this study is 3-D seismic data processing system for subsurface structure imaging and this system is developed in PC based on Linux for lower-cost computer. Basic data processing modules are originated from SU (Seismic Unix) which is widely used in 2-D seismic data processing and auxilious modules are developed for 3-D data processing. The system which is constructed by using these data processing modules is designed to GUI (Graphic User Interface) in order that one can easily control and for this purpose, GTK (Gimp Tool KiT) conventionally adapted in producing Linux application.

• Geophysics and Geophysical Exploration
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• v.6 no.2
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• pp.101-107
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• 2003

3D seismic travel-time tomography algorithm baled on Fresnel volume was developed and its feasibility was investigated by the numerical experiments. To testify the field applicability of the developed algorithm, frequency characteristics and way coverage of the crossholel seismic raw data were investigated and 3D velocity tomogram cube with about 8m spatial resolution was obtained. When compared this 3D velocity cube with the conventional 2D ray tomogram, two results were matched well. We concluded that 3D seismic tomography algorithm developed in this study has enough potential to the field application.

• Earthquakes and Structures
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• v.3 no.3_4
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• pp.231-248
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• 2012

In this study, a systematic investigation is carried out on the seismic behaviour of plane moment resisting steel frames (MRF) to repeated strong ground motions. Such a sequence of earthquakes results in a significant damage accumulation in a structure because any rehabilitation action between any two successive seismic motions cannot be practically materialised due to lack of time. In this work, thirty-six MRF which have been designed for seismic and vertical loads according to European codes are first subjected to five real seismic sequences which are recorded at the same station, in the same direction and in a short period of time, up to three days. Furthermore, the examined frames are also subjected to sixty artificial seismic sequences. This investigation shows that the sequences of ground motions have a significant effect on the response and, hence, on the design of MRF. Additionally, it is concluded that ductility demands, behaviour factor and seismic damage of the repeated ground motions can be satisfactorily estimated using appropriate combinations of the corresponding demands of single ground motions.

• 한국지구물리탐사학회:학술대회논문집
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• 2000.09a
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• pp.147-157
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• 2000

Primary purpose of the system developed in this study is 3-D seismic data processing system for underground investigation and this system is developed in PC based on Linux for lower-cost system. Basic data processing modules are originated from SU (Seismic Unix) which is widely used in 2-D seismic data processing and auxilious modules are developed for 3-D data processing The system which is constructed by using these data processing modules Is designed to GUI (Graphic User Interface) in order that one can easily control and for this purpose, GTK (Gimp Tool KiT) conventionally adapted in producing Linux application.

• Journal of the Earthquake Engineering Society of Korea
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• v.21 no.1
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• pp.69-76
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• 2017

Seismic analyses of a pile under a large rigid basement foundation embedded in the homogeneous soil layer were performed practically by a response displacement method assuming a sinusoidal wave form. However, it is hard to take into account the characteristics of a large mat foundation and a heterogeneous soil layer with the response displacement method. The response displacement method is relevant to the 2D problems for longitudinal structures such as tunnel, underground cave structure, etc., but might not be relevant with isolated foundations for building structures. In this study, seismic pile analysis by a pseudo 3D finite element method was carried out to compare numerical results with results of the response displacement method considering 3D characteristics of a foundation-soil system which is important for the building foundation analyses. Study results show that seismic analyses results of a response displacement method are similar to those of a pseudo 3D numerical method for stiff and dense soil layers, but they are too conservative for a soft soil layer inducing large soil pressures on the foundation wall and large pile displacements due to ignored foundation rigidity and resistance.