• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.525-528
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• 1999

Structural walls have been favored for the design of reinforced concrete buildings in seismic zone areas because they provide an efficient bracing system and offer great potential for lateral load resistance and drift control. Loads on structures due to earthquakes are not unlikely to reach, if not exceed, the design load levels. Hence, structural damage to walls is inevitable, and it is necessary to repair this damaged walls. Yet, information on repair method and data related to the strength and deformation characteristics of repaired walls is limited. In this study, specimens which have their aspect ratios of about 1 to 3 will be repaired. For the repairing the damaged walls, new concrete and new reinforcing bar are replaced with cracked concrete and the buckled reinforcing bar, respectively. The objective of this study is to evaluate the performance of the repaired structural walls in the capacity of strength, stiffness, and maximum deformation comparing with the undamaged walls.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.750-755
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• 1999

When the RC frame structures subjected to the seismic load, brittle shear failure of vertical members induces brittle collapse of whole structures. Failure mechanism like this is not desirable. So shear strengthening method to avoid this failure mechanism is needed. Recently, strengthening method using continuous fiber sheet is studied and used widely which have high elastic and high strength characteristics. In this study, RC columns which is strengthened by carbon fiber sheet in the form of tape or whole sheet were tested under the cyclic load. The parameter of this test is the amount of strengthening. As the amount of strengthening increase, strength, ductility and energy capacity increase. The failure mode of test results are shear and bond-split failure.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.589-594
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• 2000

The necessary strength and ductility to avoid structural damage under moderate earthquake can be achieved by properly detailed transverse reinforcement in the plastic hinge zone. However, most structural walls have a higher aspect ratio(M/Vl\ulcorner) without well confined boundary regions. Therefore there is a need for adequate detailing in the plastic hinge zone, particularly boundary regions. In this paper, the fabricated interlocking spirals is introduced as a new seismic detailing for ductile behavior of the structural walls to be able to substitute for existing complicated detailing with ties. This paper also investigates the behavior characteristics of structural walls with interlocking spirals including confinement of the concrete and strength associated with flexure and shear.

• 한국공간정보시스템학회:학술대회논문집
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• 2004.05a
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• pp.113-122
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• 2004

Cable domes deform very largely because of the characteristics of flexible hybrid system and pre-tension, and include geometrical non-linearity in those structural behavior. Especially wind load is more dominant than seismic load, because cable domes are flexible structures whose bending stiffness is very small and self-weight is very light. Therefore, in this paper, the Modified Stiffly Stable Method is applied to analyze the nonlinear dynamic behavior of cable domes and compared these results with ones of the $Newmark-{\beta}$ Method which is generally used. The Seoul Olympic Gymnastic Arena is taken as an numerical example and three kinds of models with giving each different intensity of pre-tension are selected. And dynamic nonlinear behavior of cable domes are analyzed by artificial spectrum of wind velocity wave which is similar to actual wind loads.

• Structural Engineering and Mechanics
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• v.17 no.2
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• pp.203-214
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• 2004

The dynamic response characteristics of a rectangular fluid container are investigated by using finite element method. The fluid is assumed to be linear-elastic, inviscid and compressible. A displacement-based fluid finite element was employed to allow for the effects of the fluid. A typical rectangular fluid container, which is used in recent studies, is considered for the numerical analysis. The North-South component of El Centro Earthquake records is used as input ground acceleration. Rigid and flexible fluid containers solutions are obtained for the chosen sample tank. Hydrodynamic pressures and sloshing motions are determined using Lagrangian fluid finite element. The results obtained from this study are compared with the results obtained by boundary-finite element method (BEM-FEM) and requirements of Eurocode-8. Based on the numerical analysis, some conclusions and discussions on the design considerations for rectangular fluid containers are presented.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.61-68
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• 2003

Cable domes deform very largely because of the characteristics of flexible hybrid system and pre-tension, and include geometrical non-linearity in those structural behavior. Especially wind load is more dominant than seismic loads, because cable domes are flexible structures whose stiffness is very small and self-weight is very light. Therefore, in this paper, Modified Stiffly Stable Method is applied to analyze the nonlinear dynamic behavior of cable domes and compared these results with ones of Newmark-β Method which is generally used. The Seoul Olympic Gymnastic Arena is taken as an numerical example and three kinds of models with giving each different intensity of pre-tension are selected. And dynamic nonlinear behavior of cable domes are analyzed by artificial spectrum of wind velocity wave which is similar to actual wind loads.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.3
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• pp.73-86
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• 2002

Prognostic characteristics of hypothetical tsunamis in the East Sea are discussed based on numerical model simulations of linear long wave theory and wave ray for 28 source zones of tsunamigenic earthquake selected by the seismic gap theory. As a result, the propagation patterns of tsunamis due to hypothetical earthquake are presented and analyses also lead to selection of the geographical zones with low risk of tsunamis.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.09a
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• pp.364-372
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• 2001

An orifices fluid damper(OFD) having the capacity of about 2 tons was designed and fabricated and applied to a 6-story steel structure under random excitation and seismic excitation for the confirmation of its validity on structural vibration absorbtion. The experimental results demonstrated that the addition of an OFD to the test structure is very effective in reduction of vibration level of the higher modes as well as the fundamental mode. Maxwell model was adopted to described the frequency-dependent characteristics of the fabricated OFD and the numerical simulation was carried for the test structure. It was confirmed that the experimental and numerically simulated results agree well.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.42-46
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• 2005

Ground motions with the near fault effects are studied for the seismic design and the analysis of structures. The characteristics of the velocity pulse by the forward directivity are studied and the relations between velocity pulse and earthquake magnitude are investigated. The elastic response spectra of the near fault ground motion are compared with these of the far fault ground motion. And effects on the behaviors of structures are studied by the analysis of the elastic and the inelastic single degree of freedom system in terms of the response spectrum and the ductility demand.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.110-117
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• 2005

This paper deals the shaking table tests with 1/100 scaled model followed by Scott & Iai(1989)'s similitude law for OO dam main desging section to understand nonlinear behavior characteristics of concrete dam body by earthquake wave. As earthquake wave, Hachinohe and Elcentro waves were used and acceleration and displacements are measured to analyze behaviors of dam body. For ground maximum acceleration range ($0.3^{\sim}0.9g$), the results showed linear behavior regardless of ground maximum acceleration and secured safety of structure. To analyze the behavior of dam after tension cracking, 3cm-notch was placed at the critical section of over-flowing section. As results of applying Hachinohe wave(0.8g), Even though tension cracks were formed at over-flowing section by Hachinohe wave(0.8g), it showed that the dam is stable for supporting upper stream part of water tank of dam.