• Title/Summary/Keyword: Story Shear

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Seismic performance of mid-rise steel frames with semi-rigid connections having different moment capacity

  • Bayat, Mohammad;Zahrai, Seyed Mehdi
    • Steel and Composite Structures
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    • v.25 no.1
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    • pp.1-17
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    • 2017
  • Seismic performance of hybrid steel frames defined as mixture of rigid and semi-rigid connections is investigated in this paper. Three frames with 10, 15 and 20 stories are designed with fully rigid connections and then with 4 patterns for semi-rigid connection placement, some of beam to column rigid connections would turn to semi-rigid. Each semi-rigid connection is considered with 4 different moment capacities and all rigid and semi-rigid frames consisting of 51 models are subjected to 5 selected earthquake records for nonlinear analysis. Maximum story drifts, roof acceleration and base shear are extracted for those 5 earthquake records and average values are obtained for each case. Based on numerical results for the proposed hybrid frames, story drifts remain in allowable range and the reductions in the maximum roof acceleration of 22, 29 and 25% and maximum base shear of 33, 31 and 54% occur in those 10, 15 and 20-story frames, respectively.

Evaluation of Lateral Load Resistance Capacity of a High-rise Shear Wall Apartment Based on Elasto-plastic Analaysis (정적 탄소성 해석에 의한 고층 벽식 아파트의 수평내력 검토)

  • 전대한;강호근;조한욱;이정원
    • Journal of the Earthquake Engineering Society of Korea
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    • v.2 no.4
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    • pp.31-40
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    • 1998
  • The purpose of this study is to investigate static elastoplastic behaviour and estimate ultimate resistance capacity of a high-rise apartment shear wall system subjected to a vertical distribution of lateral loading along the height. A typical 25-story two unit plan apartment is selected as a representive model. For the analysis, the pushover analysis is adopted to estimate initial elastic stiffness, post-yielding stiffness and story shear yield resistance level on each story of the structure through three-dimensional nonlinear analysis program-CANNY. In the result of elastoplastic analysis, it is observed that the yield strength of building structures is 1.6 times larger than required lateral design strength.

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High-rise Reinforced-concrete Building Incorporating an Oil Damper in an Outrigger Frame and Its Vibration Analysis

  • Omika, Yukihiro;Koshika, Norihide;Yamamoto, Yukimasa;Kawano, Kenichi;Shimizu, Kan
    • International Journal of High-Rise Buildings
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    • v.5 no.1
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    • pp.43-50
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    • 2016
  • The reinforced-concrete multi-story shear-wall structure, which can free a building from beams and columns to allow the planning of a vast room, has increasingly been used in Japan as a high-rise reinforced-concrete structure. Since this structural system concentrates the seismic force onto multi-story shear walls inside, the bending deformation of the walls may cause excessive deformation on the upper floors during an earthquake. However, it is possible to control the bending deformation to within a certain level by setting high-strength and rigid beams (outriggers) at the top of the multi-story shear walls; these outriggers restrain the bending behavior of the walls. Moreover, it is possible to achieve high energy dissipation by placing vibration control devices on the outriggers and thus restrain the bending behavior. This paper outlines the earthquake response analysis of a high-rise residential tower to demonstrate the effectiveness of the outrigger frame incorporating vibration control devices.

Effects of the earth fissure on the seismic response characteristics of a nearby metro station

  • Jiang Chang;Yahong Deng;Huandong Mu
    • 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.

Simplified Dynamic Analysis of High-Rise Buildings (고층건물의 단순화된 동적해석)

  • 이동근;황재호
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.04a
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    • pp.101-108
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    • 1993
  • A simplified dynamic analysis method for high-rise building structures is proposed in this study. In the proposed method, member forces are obtained through static analysis using story forces derived from story shear forces which are obtained using dynamic analysis procedure. Major advantage of the proposed method is in the convenience in load combinations for design analysis.

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Shaking Table Tests of 1/12-Sale R.C. Bearing-Wall system with Bottom Piloti Frames (1/12 축소 철근콘크리트 상부벽식-하부골조 건축물의 진동대 실험)

  • 이한선;고동우;권기현;김병현
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.09a
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    • pp.407-414
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    • 2001
  • The severe shortage of the available sites in the highly developed downtown area in Korea necessitates the construction of high-rise buildings which meet the need of residence and commercial activity simultaneously. The objective of this study is to investigate the seismic performance of this type of building structures. For this purpose, two 1 :12 scale 17-story reinforced concrete model structures were constructed according to the similitude law, in which the upper 15 stories have a bearing-wall system while the lower 2-story frames have two different layouts of the plan The one is a moment-resisting frame system and the other is a moment-resisting frame system with a infilled shear wall. Then, this model was subjected to a series of earthquake excitations. The test results show that the existence of shear wall reduced the shear deformation at the piloti frame, but has almost the negligible effect on the reduction of the overturning-moment angle.

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Inelastic Time History Analysis of a 5-Story Reinforced Concrete IMRF (5층 철근콘크리트 중간모멘트골조의 비탄성 시간이력해석)

  • Kang, Suk Bong;Lim, Byeong Jin
    • Journal of the Earthquake Engineering Society of Korea
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    • v.16 no.6
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    • pp.13-20
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    • 2012
  • In this study, 5-story structures were designed in accordance with KBC2009 for inelastic time history analysis of RC IMRF. Bending moment-curvature relationship for beam and column was identified with fiber model and bending moment-rotation relationship for beam-column joint was calculated with simple and unified joint shear behavior model and moment equilibrium relationship for the joint. The hysteretic behavior was simulated with three-parameter model suggested in IDARC program. The analytical results showed that the inelastic shear behavior of the joint could be neglected in the structural design for seismic design category C but the structure of category D did not satisfy the criteria of FEMA 356 for collapse prevention performance level.

Evaluation on Seismic Performance of Existing Frame retrofitted with RC CIP Infill Walls (기존 골조의 내진성능 향상을 위한 철근콘크리트 현장타설 끼움벽의 보강성능 평가)

  • Kim, Sun-Woo;Yun, Hyun-Do;Kim, Yun-Su;Ji, Sang-Kyu
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.53-56
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    • 2008
  • A reinforced concrete (RC) cast-in-place (CIP) infill wall retrofitting method may provide an improved seismic performance and economical efficiency for the non-ductile rahmen structures. In this study, four one story-one bay non-ductile frame were constructed and retrofitted with CIP infill wall to evaluate seismic performance of CIP infill wall-frame. From the test results, infill wall-frame exhibited a marked increase in shear strength compared to non-ductile RC frame specimen. But the ductility and story-drift at maximum load were decreased when shear strength of infill wall larger than that of existing RC frame. Therefore, it is confirmed that adequate reinforcement detail is required to assure sufficient seismic performance.

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Seismic response of dual structures comprised by Buckling-Restrained Braces (BRB) and RC walls

  • Beiraghi, Hamid
    • Structural Engineering and Mechanics
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    • v.72 no.4
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    • pp.443-454
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    • 2019
  • In order to reduce the residual drift of a structure in structural engineering field, a combined structural system (dual) consisting of steel buckling-restrained braced frame (BRBF) along with shear wall is proposed. In this paper, BRBFs are used with special reinforced concrete shear walls as combined systems. Some prototype models of the proposed combined systems as well as steel BRBF-only systems (without walls) are designed according to the code recommendations. Then, the nonlinear model of the systems is prepared using fiber elements for the reinforced concrete wall and appropriate elements for the BRBs. Seismic responses of the combined systems subjected to ground motions at maximum considered earthquake level are investigated and compared to those obtained from BRBFs. Results showed that the maximum residual inter-story drift from the combined systems is, on average, less than half of the corresponding value of the BRBFs. In this research, mean of absolute values of the maximum inter-story drift ratio demand obtained from combined systems is less than the 3% limitation, while this criterion has not been fulfilled by BRBF systems.

Performance-based Seismic Design of 9-Story Engineered Wood Office Building (9층 공학목재 사무소 건물의 성능기반 내진설계)

  • Chu, Yurim;Kim, Taewan;Kim, Seung Re
    • Journal of the Earthquake Engineering Society of Korea
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    • v.22 no.4
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    • pp.225-233
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    • 2018
  • One of engineered woods, glued laminated timber (GLT), can provide a constant level of performance and desired strength even if the quality of wood is low. Due to this fact, there is a growing interest in GLT using domestic species and related research has been carried out continuously. In addition, GLT is popularly being applied to the long-span or high-rise structures overseas. However, KBC 2016 does not allow the engineered woods to be used for middle and high-rise buildings by limiting height. Therefore, a proper design procedure and rationale should be clearly presented by the help of performance-based seismic design. With this background, the goal of this study is to establish a specific procedure for design of a 9-story building with RC shear walls and GLT frames according to the performance-based design of KBC 2016. The performance objectives were set according to KBC and the acceptance criteria for each goal were defined. The RC shear walls and GLT frames were designed by concrete and wood structure requirements, respectively. Analytical models were developed to reflect their nonlinear features, and both nonlinear static and dynamic analyses were conducted. Performance evaluation results showed that the shear walls have insufficient shear strength, so they were re-designed. Consequently, it has been confirmed that GLT frames can be applied to a 9-story office building with the assistance of RC shear walls and performance-based seismic design.