• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.193-200
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• 2000

Numerical analysis of slope stability is presented using slice method, static seismic analysis methods, and earthquake response analysis methods. Static seismic force is considered as 0.2g while vertical static seismic force is not considered in analysis. For earthquake response analysis, Hachinohe-wave is applied. Safety factor calculated using slice method for failure surface. Calculating methods are Bishop's method and Janhu's method. Static seismic analysis was applied using Mhor-Coulomb model and earthquake response analysis was applied using non-linear elastic model.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.108-115
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• 2000

Numerical analysis of slop stability is presented using seismic displacement, response seismic coefficient, and earthquake response analysis methods. In seismic displacement and response seismic coefficient methods, horizontal static seismic force is considered as 0.2g while vertical static seismic force is not considered in analysis. For earthquake response analysis Hahinoha-wave is applied, It is found from result that analysis using response seismic coefficient method is much more conservative than that using seismic displacement method Also, analysis result using earthquake response analysis method is somewhat less conservative about 25% when compared with that using seismic displacement method.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.04a
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• pp.144-151
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• 2001

The development history of seismic design and analysis methods considering seismic force in soil-structure dynamic interaction are presented. Determination of seismic intensity in static analysis of both seismic and modifided seismic methods is discussed and preferable method in future seismic design is proposed.

• Steel and Composite Structures
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• v.20 no.4
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• pp.777-799
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• 2016

One of the major components for performance based seismic design is accurate estimation of critical seismic demand parameters. While nonlinear seismic analysis is the most appropriate analysis method for estimation of seismic demand parameters, this method is very time consuming and complex. Single mode pushover analysis method, N2 method and multi-mode pushover analysis method, modal pushover analysis (MPA) are two nonlinear static methods that have recently been used for seismic performance evaluation of few lateral load-resisting systems. This paper further investigates the applicability of N2 and MPA methods for estimating the seismic demands of ductile unstiffened steel plate shear walls (SPSWs). Three different unstiffened SPSWs (4-, 8-, and 15-storey) designed according to capacity design approach were analysed under artificial and real ground motions for Vancouver. A comparison of seismic response quantities such as, height-wise distribution of floor displacements, storey drifts estimated using N2 and MPA methods with more accurate nonlinear seismic analysis indicates that both N2 and MPA procedures can reasonably estimates the peak top displacements for low-rise SPSW buildings. In addition, MPA procedure provides better predictions of inter-storey drifts for taller SPSW. The MPA procedure has been extended to provide better estimate of base shear of SPSW.

• Journal of the Earthquake Engineering Society of Korea
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• v.28 no.4
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• pp.205-213
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• 2024

In the seismic evaluation of underground utility tunnels, selecting an analytical method is critical to estimating reasonable seismic responses. In simplified pseudo-static analysis methods widely applied to typical seismic design and evaluation of underground tunnels in practice, it is essential to check whether the methods provide valid results for cut-and-cover tunnels buried in shallow to medium depth. The differences between the two simplified pseudo-static methods are discussed in this study, and the analysis results are compared to those obtained from FLAC models. In addition to the analysis methods, seismic site classification, overburden soil depth, and sectional configuration are considered variables to examine their effects on the seismic response of underground utility tunnels. Based on the analysis results, the characteristics derived from the concepts and details of each simplified model are discussed. Also, general observations are made for the application of simplified analysis methods.

• Journal of Ocean Engineering and Technology
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• v.19 no.1 s.62
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• pp.26-32
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• 2005

Recent earthquakes, measuring over a magnitude of 5.0, on the eastern coast of Korea, have aroused interest in earthquake analyses and the seismic design of caisson-type breakwaters. Most earthquake analysis methods, such as equivalent static analysis, response spectrum analysis, nonlinear analysis, and capacity analysis, are deterministic and have been used for seismic design and performance evaluation of coastal structures. However, deterministic methods are difficult for reflecting on one of the most important characteristics of earthquakes, i.e. the uncertainty of earthquakes. This paper presents results of probabilistic seismic hazard assessment(PSHA) of an actual caisson-type breakwater, considering uncertainties of earthquake occurrences and soil properties. First, the seismic vulnerability of a structure and the seismic hazard of the site are evaluated, using earthquake sets and a seismic hazard map; then, the seismic risk of the structure is assessed.

• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.5
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• pp.213-220
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• 2023

Seismic fragility curves play a crucial role in assessing potential seismic losses and predicting structural damage caused by earthquakes. This study compares non-sampling-based methods of seismic fragility curve derivation, particularly the probabilistic seismic demand model (PSDM) and finite element reliability analysis (FERA), both of which require employing sophisticated finite element analysis to evaluate and predict structural damage caused by earthquakes. In this study, a three-dimensional finite element model of API 5L X65, a buried gas pipeline widely used in Korea, is constructed to derive seismic fragility curves. Its seismic vulnerability is assessed using nonlinear time-history analysis. PSDM and a FERA are employed to derive seismic fragility curves for comparison purposes, and the results are verified through a comparison with those from the Monte Carlo Simulation (MCS). It is observed that the fragility curves obtained from PSDM are relatively conservative, which is attributed to the assumption introduced to consider the uncertainty factors. In addition, this study provides a comprehensive comparison of seismic fragility curve derivation methods based on sophisticated finite element analysis, which may contribute to developing more accurate and efficient seismic fragility analysis.

• Structural Engineering and Mechanics
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• v.11 no.6
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• pp.651-662
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• 2001

In order to investigate the seismic behavior and seismic design methods in the transverse direction of a shield tunnel, a series of model shaking table tests and a two-dimensional finite element dynamic analysis on the tests are carried out. Two kinds of static analytical methods based on ground-tunnel composite finite element model and beam-spring element model are proposed, and the validity of the static analyses is verified by model shaking table tests. The investigation concerns the dynamic response behavior of a tunnel and the ground, the interaction between the tunnel and ground, and an evaluation of different seismic design methods. Results of the investigation indicate that the shield tunnel follows the surrounding ground in displacement and dynamic characteristics in the transverse direction; also, the static analytical methods proposed by the authors can be used directly as the seismic design methods in the transverse direction of a shield tunnel.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1997.04a
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• pp.199-206
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• 1997

Under sever earthquake, structural elements or structures may sustain a large number of inelastic excursions. To predict seismic damage of the structures with accuracy, much research for general definition of structural collapse and seismic damage analysis is required. The ductility method, the energy method and Park and Ang method for seismic damage analysis of structural elements and structures are compared in this paper. Also, the seismic damage analysis for system-level of structure is carried out using the ESDOF-system method and Powell method. To compare tendency of the seismic damage analysis using each methods, example analysis is accomplished for several cases of different structures and different earthquake excitation.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.1
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• pp.32-40
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• 2005

Recent earthquakes over magnitude 5 in the eastern coast of Korea have aroused interests in the earthquake analyses and seismic design of breakwater structures. Most of earthquake analysis methods such as equivalent static analysis, response spectrum analysis, nonlinear analysis, and capacity analysis methods are deterministic and have been used for seismic design and performance evaluation of breakwater structures. However, deterministic methods are difficult to reflect one of the most important characteristics of earthquakes, i.e. the uncertainty of earthquakes. This paper presents results of probabilistic seismic risk assessment(PSRA) of an actual caisson type breakwater structure considering uncertainties of earthquake occurrences and soil properties. First the seismic vulnerability of a structure and the seismic hazard of the site are evaluated using earthquake sets and seismic hazard map, and then seismic risk of the structure is assessed.