• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.161-170
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• 2007

In general, deflection limit criteria of bridge design specifications would have been considered based on the static serviceability and structural stability. Dynamic serviceability induced from bridge vibration, as a comfort limit, actually has not been included in the criteria. Thus, it is necessary for dynamic serviceability to be considered in bridge vibration problems and for comfort limit on vibration to be needed for evaluating dynamic serviceability of bridges. In this paper, comfort limits of bridge structures considering the time duration exposed by vibration were examined with frequency and time dependent comfort limits, and they were evaluated by using the vibration signals measured from the existing bridges. Therefore, it is resulted that the time-dependent comfort limit considering the duration of vibration is an efficient estimate for evaluating dynamic serviceability of bridges.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.10
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• pp.923-935
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• 2007

In general, deflection limit criteria of bridge design specifications would have been considered based on the static serviceability and structural stability. Dynamic serviceability induced from bridge vibration, as a comfort limit, actually has not been included in the criteria. Thus, it is necessary for dynamic serviceability to be considered in bridge vibration problems and for comfort limit on vibration to be needed for evaluating dynamic serviceability of bridges. In this paper, comfort limits of bridge structures considering the time duration exposed by vibration were examined with frequency and time dependent comfort limits, and they were evaluated by using the vibration signals measured from the existing bridges. Therefore, it is resulted that the time-dependent comfort limit considering the duration of vibration is an efficient estimate for evaluating dynamic serviceability of bridges.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.80-85
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• 2008

In general, deflection limit criteria of bridge design specifications have been considered based on static serviceability and structural stability. Dynamic serviceability induced from bridge vibration actually has not been included in the criteria. Thus, it is necessary for comfort limit to be considered in order to check dynamic serviceability on bridge vibration. In this study, the comfort limit of bridge structures based on the RMQ and VDV considering the signal fluctuation effectively and the time duration exposed has been constructed. The comfort limit developed in time domain was verified by using vibration signals directly measured from the existing bridges. Comparing the developed comfort limit with the conventional ones defined in frequency domain, it is shown that the comfort limit developed in time domain would be more feasible for evaluating quantitatively the serviceability due to bridge vibration. Using the Bridge-train interaction analysis program, dynamic response of the bridge by the stiffness change were obtained for several railway bridges. And, a stiffness limit satisfying the bridge vibration serviceability was estimated by compared with comport limit. From the results, a new deflection limit on bridge structures satisfying the vibration serviceability could be proposed by comparing with the conventional deflection limit criteria.

• Journal of the Korean Society for Railway
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• v.11 no.5
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• pp.489-498
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• 2008

In general, deflection limit criteria of bridge design specifications have been considered based on static serviceability and structural stability. Dynamic serviceability induced from bridge vibration actually has not been included in the criteria. Thus, it is necessary for deflection limit to be considered in order to check dynamic service- ability on bridge vibration. In this study, The allowable displacement of Korea Railway Bridge Design Specifications is compared to the frequency domain comfort limit and analyzed france code and japanese code. Korea Railway Bridge Design Specifications is regulated based on the train speed. Such is because the vibration time duration is partly considered. but this criteria is not satisfied with comfort limit. and, it is estimated to be capable to provide deflection limit considering dynamic serviceability. In order to evaluate the dynamic serviceability of various types of railway bridges in current public were selected and their dynamic signals were measured. and the result of the bridge-train interaction analysis according to the changes in bridge stiffness was compared to the comfort limit to suggest the stiff-ness limit to the dynamic serviceability, which should conveniently be applied at the field.

• Wind and Structures
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• v.14 no.6
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• pp.559-582
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• 2011

This paper presents an integrated wind-induced dynamic analysis and computer-based design optimization technique for minimizing the structural cost of general tall buildings subject to static and dynamic serviceability design criteria. Once the wind-induced dynamic response of a tall building structure is accurately determined and the optimal serviceability design problem is explicitly formulated, a rigorously derived Optimality Criteria (OC) method is to be developed to achieve the optimal distribution of element stiffness of the structural system satisfying the wind-induced drift and acceleration design constraints. The effectiveness and practicality of the optimal design technique are illustrated by a full-scale 60-story building with complex 3D mode shapes. Both peak resultant acceleration criteria and frequency dependent modal acceleration criteria are considered and their influences on the optimization results are highlighted. Results have shown that the use of various acceleration criteria has different implications in the habitability evaluations and subsequently different optimal design solutions. The computer based optimization technique provides a powerful tool for the lateral drift and occupant comfort design of tall building structures.

• KIEAE Journal
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• v.8 no.6
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• pp.63-70
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• 2008

Slim floor construction is becoming used throughout many countries. It combines the advantages of flat slab construction with significant inherent resistance to fire. The slim floor system with web openings leads to the reduction of its self-weight. Although the system has enough strength and stiffness, it is necessary to evaluate and improve the effects of dynamic vibration to be able to annoy the residents. Thus, this study evaluates the serviceability of vibration effects based on the dynamic test of five slim composite beams. Based on the experimental results, the initial stiffness and natural frequency of all specimens exhibit the similar trend regardless of the opening and the shape of cross section. The decrease in natural frequency is deeply related to the reduction in the stiffness of specimens and thus, it can be concluded that the damage of slim composite floor can be detected by the measurement of natural frequency instead of the load-carrying capacity and the stiffness.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.1
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• pp.65-71
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• 2009

In this study, dynamic serviceability of PSC, PreStressed Concrete, simple railway bridge with 25m span was estimated. All of the high speed and general train loads were considered at estimation. Natural frequency is estimated about 8Hz and includes within optimum natural frequency extent of the railway bridge. Also, the bridge was detected that resonance occurrence possibility does not exist. When travel the Moogunghwa train, acceleration response was measured to 0.43g that exceed limitation value 0.35g. Also, rotation angle of girders end did not satisfy design standard of railway bridge for high speed train, but impact coefficient and deflection satisfied design standard. As a result, that railway bridge was detected that is securing dynamic safety and serviceability partially, but methods to decrease vibration acceleration response are required.

• Journal of Korean Association for Spatial Structures
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• v.4 no.1 s.11
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• pp.61-68
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• 2004

The wind tracker and structural monitoring system recorded wind and dynamic response data. The measured building is located in the moutatin in Sokcho. The damping ratio and natural frequency were analysed in this paper to obtain amplitude dependence. Amplitude dependent damping was showed clearly in the increasing rate of 9%. The tendency of dynamic properties of building obtained here are useful for the validation of dynamic properties of buildings in the evaluation of serviceability.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.955-960
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• 2000

This paper evaluates the serviceability of vibration that is induced by people's walking and running when the long span hollow core slab is used. The dynamic characteristics like a natural frequency and a ramping ratio are found by impact loading test on the mock-up structures. Also, the human induced loading test output is evaluated by the various serviceability criteria. As the various serviceability criteria satisfy with this result, the vibration problem of relevant slab caused by people's behavior does not matter.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.458-461
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• 2008

The primary objective of this study is to provide simple analytical tools to estimate dynamic characteristics of steel framed floor system in hospital building for vibration serviceability due to human activities, bogie, medical equipment. and so on. In order to evaluate the dynamic characteristics and vibration levels according to steel framed floor system, we had executed impact test and measurement on steel structure floor system in various hospital buildings. But perhaps most importantly, how to make the most of deduced design factor for design of hospital building. therefore we presented the access method such as the three-dimensional F.E. numerical analysis on the basis of the design drawing, and the properties of all floors for estimation of vibration level in hospital building.