• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.58-63
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• 1999

In and around the Korean Peninsula 22 intraplate earthquake mechanisms since 1936 were analyzed to understand the regional stress orientation and tectonics. These 22 earthquakes are largest ones in this century and may represent the characteristics of earthquake in the region. Focal mechanism of earthquakes in the region show predominant strike-slip faulting with small amount of thrust components. The average P-axis is almost horizontal ENE- WSW. Studied data are compared with neighboring intraplate region in order to understand the tectonic regime in far est Asia. In northeastern China strike-slip faulting is dominant and nearly horizontal average P-axis in ENE- WSW is very similar with the Korean Peninsula. On the other hand in the eastern part of East Sea thrust faulting is dominant and average P-axis is horizontal with ESE- WSW This indicate that not only the subducting Pacific Plate in east but also the indenting Indian Plate controls earthquake mechanism in the far east of the Eurasian Plate.

• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.1-5
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• 2008

In and around the Korean Peninsula, 9 intraplate earthquake mechanisms since 1936 were analyzed to understand the regional stress orientation and tectonics. These earthquakes are largest ones in this century and may represent the characteristics of earthquake in this region. Focal mechanism of these earthquakes show predominant strike-slip faulting with small amount of thrust components. The average P-axis is almost horizontal ENE-WSW. This indicate that not only the subducting Pacific Plate but also the indenting Indian Plate controls earthquake mechanism in the far east of the Eurasian Plate.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.3
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• pp.283-288
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• 2011

For the earthquake resistance design designer should provide that structural yielding process is principally designed with the ductile failure mechanism. In order to get the ductile failure mechanism for typical bridges, pier columns yielding should occur before that of connections. However domestic bridge design with unnecessary stiff substructure leads to unnecessary seismic loads and makes it difficult to get the ductile failure mechanism. Such a problem arises from the situation that earthquake resistant design is not carried out in the preliminary design step. In this study a typical bridge is selected as an analysis bridge and design strengths for connections and pier columns are determined in the preliminary design step by carrying out earthquake resistant design. It is shown through this procedure that it is possible to get the ductile failure mechanism with structural members determined by other design.

• Structural Engineering and Mechanics
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• v.1 no.1
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• pp.31-46
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• 1993

The motivations of the application of shakedown analysis to the earthquake-resistant design of ductile moment-resisting steel structures are presented. The problems which must be solved with this application are also addressed. The illustrative results from a series of static and time history nonlinear analyses of one-bay three-story steel frame and the related discussions have shown that the incremental collapse may be the critical design criterion in case of earthquake loading. Based on the findings, it was concluded that the inelastic excursion mechanism for alternation load pattern, such as in earthquake, should be the sidesway mechanism of the whole structure for the efficient mobilization of the structural energy dissipating capacity and that the shakedown analysis technique can be used as a tool to ensure this mechanism.

• Structural Engineering and Mechanics
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• v.6 no.8
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• pp.841-856
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• 1998

During the 1995 Hyogoken-Nanbu Earthquake, a reinforced concrete building, called Jeunesse Rokko, suffered intermediate damage by forming a beam-yielding (weak-beam strong-column) mechanism, which has been regarded as the most desirable earthquake resisting mechanism throughout the world. High cost to repair damage at many beam ends and poor appearance expected after the repair work made the owner decide to tear down the building. Nonlinear earthquake response analyses were conducted to simulate the behavior of the building during the earthquake. The influence of non-structural members was considered in the analysis. The calculated results were compared with the observed damage, especially the location of yield hinges and compression failure of spandrel beams, and the degree of cracking in columns and in column-girder connections.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.4
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• pp.75-81
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• 2001

Fuzzy supervisory control method is studied for the active control of earthquake excited structures. The proposed algorithm supervises and tunes previously designed control gains by evaluating the state of a structure through the fuzzy inference mechanism, which uses the information of relative displacements and velocities. Example designs and numerical simulations of earthquake exited three degrees of freedom structures are performed to prove the validity of the proposed control algorithm. Comparative results with conventional LQR method show that the proposed method is effective for the vibration suppression of earthquake excited structures.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.2
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• pp.187-192
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• 2016

While structures are designed within elastic range by other designs, plastic behavior of structures should be verified and controlled in order to prevent structural collapse by the earthquake resistant design. No Collapse Requirement for typical bridges is to avoid falling down of superstructure by way of plastic behavior of certain structural elements and to operate emergency vehicles after earthquake. Such plastic behavior is restricted to connections or pier columns and appropriate measures are required for each case. Earthquake Resistant Design part of Roadway Bridge Design Code provides design processes for Ductile Collapse Mechanism by forming plastic hinges at pier columns. Also for bridges with reinforced concrete piers ductility-based design processes are provided as an appendix constructing Brittle Collapse Mechanism with connection yielding. In this study, a typical bridge with steel bearing connections and reinforced concrete piers is selected and No Collapse Design procedure considering both Ductile and Brittle Collapse Mechanism is proposed together with revisions required for the Earthquake Resistant Design part.

• Earthquakes and Structures
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• v.5 no.6
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• pp.753-779
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• 2013

One of the most important issues in progressive collapse mechanism of the buildings is evaluation of the collapse distribution in presence of the earthquake loads. Here, collapse propagation is investigated by tracking down the location and type of the collapsed beam and column elements, from the first element to the entire buildings. 6-story reinforced concrete ordinary moment resisting frame buildings with one directional mass eccentricity of 0%, 5%, 15% and 25% are studied to investigate differences among the progressive collapse mechanism of the regular and irregular buildings. According to the results of the nonlinear time history analyses, there are some patterns to predict progressive collapse scenarios in beam and column elements of the similar regular and irregular buildings. Results also show that collapse distribution patterns are approximately independent of the earthquake records.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.69-74
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• 2007

The source mechanism parameters of the Ulgin earthquake on 29 May 2004 are analyser using moment tensor inversion technique. The Green's function are calculated for the Kim's(1985) crust model of southern Korean Peninsula. Results derived from the Ulgin earthquake show the dependence of azimuthal station distribution and epicentral distances. final results show fairly good agreement to those of other authors. the focal mechanism for the Ulgin earthquake is found to be oblique reverse motion with NNE strike. The focal depth is estimated to be 10-12km.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.3
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• pp.163-172
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• 2014

The purpose of earthquake resistant design for typical bridges is the No Collapse Design and the Earthquake Resistant Design Part of Roadway Bridge Design Code provides a design process to construct the Ductile Failure Mechanism for the bridge structure. However, if it is not practical to provide the Ductile Failure Mechanism due to structure types or site conditions, the Brittle Failure Mechanism is an alternative way to get the No Collapse Design. As well as the existing design process constructing the Ductile Failure Mechanism, the Earthquake Resistant Design Part provides a ductility-based design process as an appendix, which is prepared for bridges with reinforced concrete piers. According to the new design process, designer determines a required response modification factor for substructure and transverse reinforcement for confinement therefrom. In this study, a typical bridge with steel bearing connections and reinforced concrete piers is selected for which the existing as well as the ductility-based design processes are applied and different results from the two design processes are identified. Based on the results, an earthquake resistant design procedure is proposed in which designers should consider the two design processes.