• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.1
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• pp.154-162
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• 2019

Large scale damage has been globally increased due to natural disasters such as earthquake. Although a variety of studies secured seismic performance of buildings, casualties and economic loss have occurred because of poor security of seismic performance in non-structural components. Structure's location on which non-structural components are installed and characteristics of vibration occurring on each position of structures are varied, so a response spectrum is required for each position of structures. In addition, a response spectrum occurring in a structure is different, depending on the form of it and positions on which it is installed. Therefore, selection of a response spectrum is important, so a definite method for calculating the response spectrum which acts on non-structural components is necessary. A method for choosing a response spectrum is suggested in this paper, and a structural analysis was conducted with the suggested method, by selecting a ground response spectrum and a structural system, which may occur in Korea. Moreover, it helps create a response spectrum necessary for a seismic test of non-structural components, by suggesting the method for deduction it, with a simple formula.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.1
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• pp.29-34
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• 2022

In this paper, the floor acceleration for the seismic design of non-structural elements was evaluated using the core shape as a planar variable. Linear time history analysis using 20 models with 5 different planes and 4 different floors on each plane depending on the change in the shape (position and specific gravity) of the core in the square biaxially symmetric plane was performed. The analysis confirmed that the torsional amplification of the floor acceleration was up to 1.7 times in the plane subjected to eccentricity depending on the position of the core, and the effect of torsion was the greatest in the middle floor of the structure. In a plane where only the specific gravity of the core was changed without eccentricity, when the period was less than 0.4694 s, the maximum floor acceleration decreased in the lower floors and increased in the upper floors as the period increased. Conversely, when the period was 0.4694 s or more, it was confirmed that the floor acceleration increased in the lower part and decreased in the upper part as the period increased.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.43 no.6
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• pp.68-83
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• 2014

• Magazine of the Korean Society of Hazard Mitigation
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• v.6 no.4 s.23
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• pp.65-72
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• 2006

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.2
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• pp.1-8
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• 2020

In the case of power plant facilities, seismic stability of non-structural elements is important. In particular, Cabinet structures to which electrical equipment is attached, should have functional safety against earthquakes. Therefore, in this study the dynamic characteristics of non-structural elements inside existing power plant buildings were identified and the response level generated during dynamic behavior was analyzed. In addition, The steel plate dampers were adopted and adjusted to suit the size of the target equipment. In order to derive the optimal seismic reinforcement, the variables according to the attachment location were set and the responses were analyzed by the seismic movement input before and after reinforcement.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.5
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• pp.117-124
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• 2019

Nonstructural elements are installed according to the function of a building, and refer to the elements other than a structural system that resists external loads. Although the nonstructural elements had the largest part of seismic loss of buildings, seismic design of buildings mainly focuses on structural system and the seismic design of nonstructural elements are rarely conducted. In this study, the seismic design provisions of nonstructural elements presented in Uniform Building Code (UBC) and International Building Code (IBC) were investigated in order to analyze the seismic design considerations of nonstructural elements presented in Korean Building Code (KBC). The results showed that the equivalent static load applied to seismic design of nonstructural elements was revised to take into consideration a total of five items such as effective ground acceleration, vertical amplification factor, response amplification factor, response modification factor, importance factor.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2017.11a
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• pp.145-146
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• 2017

최근 세계적으로 많은 지진이 발생하고 있으며 기상이변으로 인한 자연재해로 인해 주요 시설물들의 안전성에 관한 관심이 증가하고 있는 추세이다. 특히 비구조 요소의 경우 구조 요소보다 건설 초기 투자비용이 높아 지진이 발생하였을 때 많은 피해가 발생할 가능성이 있으며 비구조 요소의 파괴는 심각한 2차피해로 발전 될 수 있으므로 내진안전성 평가는 반드시 이루어져야 한다고 볼 수 있다. 따라서 본 연구에서는 압착식 조인트의 접촉을 고려한 수계소화설비 파이프라인의 내진성능 평가를 위한 비선형 유한요소 모델을 구축하였다.

• Computational Structural Engineering
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• v.10 no.1
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• pp.62-69
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• 1997

본 고에서는 고층건물의 건설과정에서 발생하는 시간의 진행에 따른 기둥의 (장기)변형을 정확히 예측하고 이를 시공중에 보정하도록 함으로써 비구조요소의 강도와 사용을 만족시키기 위한 방법론을 제시하였다. 이 방법론은 실험적 통계치를 기초로 한 약산해법으로서 실무에 쉽게 적용할 수 있다. 52층 RC 건물에 대한 적용 결과 기둥에 발생하는 축소량에 가장 큰 영향을 미치는 것은 탄성변형이며, 건조수축의 효과가 가장 미세한 것으로 나타났다. 그러나, 2년 이상의 장기 변형이 지속될 경우 크립변형의 영향이 탄성변형에 비해 더욱 증가할 것으로 판단된다. 고층의 RC건물인 경우 기둥간 부등축소량의 최대치(=최대 시공오차)는 중간층 근처에서 발생하는 것으로 나타났다.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.3
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• pp.121-128
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• 2020

In this paper, the ASCE 7 equivalent static approach for seismic design of non-structural elements is critically evaluated based on the measured floor acceleration data, theory of structural dynamics, and linear/nonlinear dynamic analysis of three-dimensional building models. The analysis of this study on the up-to-date database of the instrumented buildings in California clearly reveals that the measured database does not well corroborate the magnitude and the profile of the floor acceleration as proposed by ASCE 7. The basic flaws in the equivalent static approach are illustrated using elementary structural dynamics. Based on the linear and nonlinear dynamic analyses of three-dimensional case study buildings, it is shown that the magnitude and distribution of the PFA (peak floor acceleration) can significantly be affected by the supporting structural characteristics such as fundamental period, higher modes, structural nonlinearity, and torsional irregularity. In general, the equivalent static approach yields more conservative acceleration demand as building period becomes longer, and the PFA distribution in long-period buildings tend to become constant along the building height due to the higher mode effect. Structural nonlinearity was generally shown to reduce floor acceleration because of its period-lengthening effect. Torsional floor amplification as high as 250% was observed in the building model of significant torsional irregularity, indicating the need for inclusion of the torsional amplification to the equivalent static approach when building torsion is severe. All these results lead to the conclusion that, if permitted, dynamic methods which can account for supporting structural characteristics, should be preferred for rational seismic design of non-structural elements.

• Journal of the Earthquake Engineering Society of Korea
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• v.26 no.3
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• pp.105-116
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• 2022

Seismic demand on nonstructural components (NSCs) is highly dependent on the coupled behavior of a combined supporting structure-NSC system. Because of the inherent complexities of the problem, many of the affecting factors are inevitably neglected or simplified based on engineering judgments in current seismic design codes. However, a systematic analysis of the key affecting factors should establish reasonable seismic design provisions for NSCs. In this study, an idealized 2-DOF model simulating the coupled structure-NSC system was constructed to analyze the parameters that affect the response of NSCs comprehensively. The analyses were conducted to evaluate the effects of structure-NSC mass ratio, structure, and NSC nonlinearities on the peak component acceleration. Also, the appropriateness of component ductility factor (R_p) given by current codes was discussed based on the required ductility capacity of NSCs. It was observed that the responses of NSCs on the coupled system were significantly affected by the mass ratio, resulting in lower accelerations than the floor spectrum-based response, which neglected the interaction effects. Also, the component amplification factor (a_p) in current provisions tended to underestimate the dynamic amplification of NSCs with a mass ratio of less than 15%. The nonlinearity of NSCs decreased the component responses. In some cases, the code-specified R_p caused nonlinear deformation far beyond the ductility capacity of NSCs, and a practically unacceptable level of ductility was required for short-period NSCs to achieve the assigned amount of response reduction.