• Structural Engineering and Mechanics
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• 제62권2호
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• pp.209-224
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• 2017

Elevated water tanks are considered as important structures due to its post-earthquake requirements. Elevated water tank on reinforced concrete frame staging is widely used in India. Different response reduction factors depending on ductility of frame members are used in seismic design of frame staging. The study on appropriateness of response reduction factor for reinforced concrete tank staging is sparse in literature. In the present paper a systematic study on estimation of key components of response reduction factors is presented. By considering the various combinations of tank capacity, height of staging, seismic design level and design response reduction factors, forty-eight analytical models are developed and designed using relevant Indian codes. The minimum specified design cross section of column as per Indian code is found to be sufficient to accommodate the design steel. The strength factor and ductility factor are estimated using results of nonlinear static pushover analysis. It was observed that for seismic design category 'high' the strength factor has lesser contribution than ductility factor, whereas, opposite trend is observed for seismic design category 'low'. Further, the effects of staging height and tank capacity on strength and ductility factors for two different seismic design categories are studied. For both seismic design categories, the response reduction factors obtained from the nonlinear static analysis is higher than the code specified response reduction factors. The minimum dimension restriction of column is observed as key parameter in achieving the desired performance of the elevated water tank on frame staging.

• Structural Engineering and Mechanics
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• 제67권6호
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• pp.587-601
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• 2018

Elevated water tanks are inverted pendulum type structures where drift limit is an important criterion for seismic design and performance evaluation. Explicit drift criteria for elevated water tanks are not available in the literature. In this study, probabilistic approach is used to determine maximum drift limit for damage state of yielding and damage state of collapse for the elevated water tanks supported on RC frame staging. The two damage states are defined using results of incremental dynamic analysis wherein a total of 2160 nonlinear time history analyses are performed using twelve artificial spectrum compatible ground motions. Analytical fragility curves are developed using two-parameter lognormal distribution. The maximum allowable drifts corresponding to yield and collapse level requirements are estimated for different tank capacities. Finally, a single fragility curve is developed which provides maximum drift values for the different probability of damage. Further, for rational consideration of the uncertainties in design, three confidence levels are selected and corresponding drift limits for damage states of yielding and collapse are proposed. These values of maximum drift can be used in performance-based seismic design for a particular damage state depending on the level of confidence.

• Structural Engineering and Mechanics
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• 제9권6호
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• pp.615-636
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• 2000

Some elevated water tanks have failed due to torsional vibrations in past earthquakes. The overall axisymmetric structural geometry and mass distribution of such structures may leave only a small accidental eccentricity between centre of stiffness and centre of mass. Such a small accidental eccentricity is not expected to cause a torsional failure. This paper studies the possibility of amplified torsional behaviour of elevated water tanks due to such small accidental eccentricity in the elastic as well as inelastic range; using two simple idealized systems with two coupled lateral-torsional degrees of freedom. The systems are capable of retaining the characteristics of two extreme categories of water tanks namely, a) tanks on staging with less number of columns and panels and b) tanks on staging with large number of columns and panels. The study shows that the presence of a small eccentricity may lead to large displacement of the staging edge in the elastic range, if the torsional-to-lateral time period ratio $({\tau})$ of the elevated tanks lies within a critical range of 0.7< ${\tau}$ <1.25. Inelastic behaviour study reveals that such excessive displacement in some of the reinforced concrete staging elements may cause unsymmetric yielding. This may lead to progressive strength deterioration through successive yielding in same elements under cyclic loading during earthquakes. Such localized strength drop progressively develop large strength eccentricity resulting in large localized inelastic displacement and ductility demand, leading to failure. So, elevated water tanks should have ${\tau}$ outside the said critical range to avoid amplified torsional response. The tanks supported on staging with less number of columns and panels are found to have greater torsional vulnerability. Tanks located near faults seem to have torsional vulnerability for large ${\tau}$.

• 디지털융복합연구
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• 제17권6호
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• pp.373-380
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• 2019

본 연구에서는 애니메이션 산업계에서 자신만의 독창적인 작품 세계를 구축하여 인정받고 있는 톰 무어 감독의 장편 애니메이션 <바다의 노래>에 나타나는 평면적 스테이징을 분석하여 서사구조를 위한 시각적 장치 및 영상에서 나타나는 상징과 화면 구성요소를 살펴보고자 한다. 연구방법으로는 우선 스테이징에 대한 일반적 이론을 파악하고 <바다의 노래>에서 평면적 스테이징이 구체적으로 드러나는 장면을 추출 후 분석하며, 이를 정리하여 톰 무어 감독의 평면적 스테이징 연출 요소 및 특징을 밝히도록 한다. 그 결과 <바다의 노래>에서는 기본도형을 활용한 화면 구성과 켈트 전통문양인 나선형의 조형적 상징성을 내포한 화면 구성, 균형적 화면구도를 통한 안정적이고 평면적 프레임 표현, 역원근법을 사용한 시대적 배경 표현과 평면적 조형성을 더욱 강조할 수 있는 연출상의 특징이 나타났다. 이를 통해 2차원의 평면성이 더욱 극대화되어 애니메이션 전반에 걸쳐 동화책의 삽화를 보는듯한 느낌이 강조되었다. 아일랜드의 전통문화를 계승하기 위해 자국의 설화를 바탕으로 애니메이션을 제작한 톰 무어 감독은 서사를 돕는 평면적 스테이징으로 애니메이션의 독창적인 표현성과 작품성을 높이며 세계적으로 주목을 받고 있다. 본 연구가 흥행성과 작품성 모두를 만족하는 독창적이고 우수한 장편 애니메이션을 제작할 수 있도록 업계 종사자들 및 관련 연구자들의 기초자료로 활용되기를 기대한다.