• Journal of the Korean Professional Engineers Association
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• v.38 no.5
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• pp.5-9
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• 2005

The seismic design provisions of the 2005 KBC has been based on the 2000 IBC and has considered the building code situations in Korea. There are site ground motion, soil class, seismic design category in the significant changes of the 2005 KBC. In the case of soft soil condition, the response spectrum acceleration of the 2005 KBC is larger than that of previous code. To reduce the seismic force of the 2005 KBC, it need to introduce the eqrthauke force resisting system with high ductility.

• Journal of the Earthquake Engineering Society of Korea
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• v.21 no.5
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• pp.245-254
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• 2017

The building which are essential for disaster recovery is classified as a special seismic use group. Especially, achievement of seismic performance is very important for the hospital, so the hospital should be able to maintain its function during and right after an earthquake without significant damage on both structural and non-structural elements. Therefore, this study aimed at checking the seismic performance of a hospital building, but which was limited to structural elements. For the goal, a plan with a configuration of general hospitals in Korea was selected and designed by two different seismic-force-resisting systems. In analytical modeling, the shear behavior of the wall was represented by three inelastic properties as well as elastic. Nonlinear dynamic analyses were conducted to evaluate the performance of structural members. The result showed that the performance of shear walls in the hospital buildings was not satisfied regardless of the seismic-force-resisting systems, while the demands on the beams and columns did not exceed the capacities. This is the result of only considering the shear of the wall as the force-controlled action. When the shear of the wall was modeled as inelastic, the walls were yielded in shear, and as the result, the demands for frames were increased. However, the increase did not exceed the capacities of the frames members. Consequently, since the performance of walls is significant to determine the seismic performance of a hospital building, it will be essential to establish a definite method of modeling shear behavior of walls and judging their performance.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.98-99
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• 2018

Seismic retrofitting technologies have been paid attention to structural engineers for rehabilitations of existing building structures vulnerable to seismic loading conditions. This paper introduces the traditional strengtheing method applying externally-bonded steel frames to column and beam elements, and compares with the improved scheme using the frames with additional energy dissipation systems. Throughout experimental studies, it was observed that the method can be effective for promoting the seismic performance of seismic force-resisting systems by guaranteeing strong column-weak beam mechanism. Compared to the traditional manner, it was found that the new scheme can be more efficient for confirming capacity design concept, while energy dissipation systems can provide additional damping effects corresponding to lateral deformation which occurs at seismic force-resisting systems exposed to seismic excitations.

• Geomechanics and Engineering
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• v.20 no.1
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• pp.43-54
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• 2020

The limit analysis and response surfaces method were combined to investigate the reliability of pressurized tunnel faces subjected to seismic force. The quasi-static method was utilized to introduce seismic force into the tunnel face. A 3D horn failure mechanism of pressurized tunnel faces subjected to seismic force was constructed. The collapse pressure of pressurized tunnel faces was solved by the kinematical approach. The limit state equation of pressurized tunnel faces was obtained according to the collapse pressure and support pressure. And then a reliability model of pressurized tunnel faces was established. The feasibility and superiority of the response surfaces method was verified by comparing with the Monte Carlo method. The influence of the mean of soil parameters and support pressure, variation coefficients, distribution type and correlation of c-φ on the reliability of pressurized tunnel faces was discussed. The reasonable safety factor and support pressure required by pressurized tunnel faces to satisfy 3 safety levels were presented. In addition, the effects of horizontal seismic force, vertical seismic force and correlation of k_h-k_v on the reliability of pressurized tunnel faces were also performed. The method of this work can give a new idea for anti-seismic design of pressurized tunnel faces.

• Journal of Korean Association for Spatial Structures
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• v.7 no.6
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• pp.103-110
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• 2007

Only horizontal seismic waves are often applied as designed load to a rectangular rigid frame because the influence of vertical seismic waves is considered small so as to be able to ignore it. But, as for the seismic responses of shell and spatial structures, the responses in the vortical direction is significantly amplified and the vertical responses are amplified even if they are subjected to the horizontal seismic wave only. And also, the horizontal and vertical seismic responses of shell and spatial structures are amplified by vortical seismic waves. An arch has been often used as the main structure component of the large spatial structures and is the mostly simple structure with the seismic response characteristics of the spatial structures. In this paper, for arches as a simple example of the shell and spatial structures, the dynamic characteristics, when the structures are subjected to the horizontal and vertical seismic wave at the same time, are studied, and the horizontal and vertical static seismic force, which have simple forms but hold the response characteristics of arches, are proposed.

• Journal of the Korean Society of Safety
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• v.24 no.4
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• pp.74-81
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• 2009

In this study, the seismic performance of RC school buildings which were not designed according to earthquake-resistance design code were evaluated by using response spectrum and push-over analyses. The torsional amplification effect due to plan irregularity is considered and then the efficiency of seismic retrofitting methods such as RC shear wall, steel frame, RC frame and PC wing wall was investigated. The analysis result indicate that the inter-story drift concentrated in the first floor and most plastic hinge forms at the column of the first story. Among the retrofitting methods, the PC wing wall has the highest seismic performance in strength and story drift aspect. Especially, it can make building ductile behavior due to the concentrated inter-story drift at the first column hinge is distributed overall stories. The axial force, shear force and moment magnitude of existing elements significantly decreased after retrofitting. However, the axial and shear force of the elements connected to the additional retrofitting elements increased, and especially the boundary columns at the end of the retrofitting shear wall should be reinforced for assuring the enhancement of seismic performance.

• 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.

• Earthquakes and Structures
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• v.24 no.1
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• pp.53-64
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• 2023

Earth fissures with several kilometers will inevitably approach or cross the metro line, significantly threatening the safety of the underground structure in the earth fissure site. However, the influence of the earth fissure site's amplification effect on the metro station's dynamic response is still unclear. A representative earth fissure in Xi'an was taken as an example to establish a numerical model of a metro station in the earth fissure site. The dynamic response characteristics of the metro stations at different distances from the earth fissure under various seismic waves were calculated. The results show that the existence of the earth fissure significantly amplifies the dynamic response of the nearby underground structures. The responses of the axial force, shear force, bending moment, normal stress, horizontal displacement, inter-story drift, and relative slip of the metro station were all amplified within a specific influence range. The amplification effect increases with the seismic wave intensity. The amplification effect caused by the earth fissure has relatively weak impacts on the axial shear, shear force, bending movement, normal stress, and horizontal movement; slightly larger impacts on the inter-story drift and acceleration; and a significant impact on the relative slip. The influence ranges of the axial force and normal stress are approximately 20 m. The influence ranges of the acceleration and inter-story drift can reach 30 m. Therefore, the seismic fortification level of the underground structure in the earth fissure site needs to be improved.

• Earthquakes and Structures
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• v.26 no.3
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• pp.229-237
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• 2024

This paper studied the subgrade spring stiffness and its influencing factors in the seismic deformation method of circular tunnel. Numerical calculations are performed for 3 influencing factors: stratum stiffness, tunnel diameter and burial depth. The results show that the stratum stiffness and tunnel diameter have great influence on the subgrade spring stiffness. The subgrade spring stiffness increases linearly with stratum stiffness increasement, and decreases with the tunnel diameter increasement. When the burial depth ratio (burial depth/tunnel diameter) exceeds to 5, the subgrade spring stiffness has little sensitivity to the burial depth. Then, a proposed formula of subgrade spring stiffness for the seismic deformation method of circular tunnel is proposed. Meanwhile, the internal force results of the seismic deformation method are larger than that of the dynamic time history method, but the internal force distributions of the two methods are consistent, that is, the structure exhibits elliptical deformation with the largest internal force at the conjugate 45° position of the circular tunnel. Therefore, the seismic deformation method based on the proposed formula can effectively reflect the deformation and internal force characteristics of the tunnel and has good applicability in engineering practice.

• Nuclear Engineering and Technology
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• v.52 no.3
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• pp.654-659
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• 2020

The reliability of the spent fuel pool instrument is very important for the security of nuclear power plant, especially during the earthquake. The effect of the fluid force on the vibration characteristics of the flexible tube of the spent fuel pool instrument needs comprehensive analysis. In this paper, based on the potential flow theory, the hydrodynamic pressures acting on the flexible tube were obtained. A mathematical model of a flexible tube was constructed to obtain the dynamic response considering the effects of seismic load and fluid force, and a computer code was written. Based on the mathematical model and computer code, the maximum stresses of the flexible tube in both safe shutdown earthquake and operating basis earthquake events on the spent fuel pool with three typical water levels were calculated, respectively. The results show that the fluid force has an obvious effect on the stress and strain of the flexible tube in both safe shutdown earthquake and operating basis earthquake events.