• Title/Summary/Keyword: Weak-story

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Seismic Performance Evaluation of Small-size Pilloti-type Reinforced Concrete Buildings using Nonlinear Dynamic Analysis (비선형 동적해석을 이용한 소규모 필로티형 철근콘크리트 건축물의 내진성능평가)

  • Yoo, Changhwan;Kim, Taewan;Chu, Yurim
    • Journal of the Earthquake Engineering Society of Korea
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    • v.20 no.4
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    • pp.191-199
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    • 2016
  • Piloti-type building is one of typical vertical atypical buildings. These buildings can fail by weak-story or flexible-story mechanism on the first story. They should be designed by taking into account the special seismic load, but those less than six stories are not required to confirm the seismic performance from structural engineers in Korea. For this reason, small-size pilloti-type RC buildings need to be checked for seismic performance. Based on this background, this study performed nonlinear dynamic analysis using the PERFORM-3D for small-size pilloti-type RC buildings and assessed their seismic performance. Examples are two through four story buildings with and without walls in the first story. The walls and columns in the first story satisfied the target performance in the basic of flexural behavior due to quite a large size and reinforcement. However, wall shear demands exceed shear strength in some buildings. When designed for KBC2009, wall shear strength exceed shear demand in some buildings, but still does not in others. Consequently, wall shear must be carefully checked in both existing and new small-size pilloti-type RC buildings.

Experimental research on seismic behavior of a composite RCS frame

  • Men, Jinjie;Zhang, Yarong;Guo, Zhifeng;Shi, Qingxuan
    • Steel and Composite Structures
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    • v.18 no.4
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    • pp.971-983
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    • 2015
  • To promote greater acceptance and use of composite RCS systems, a two-bay two-story frame specimen with improved composite RCS joint details was tested in the laboratory under reversed cyclic loading. The test revealed superior seismic performance with stable load versus story drift response and excellent deformation capacity for an inter-story drift ratio up to 1/25. It was found that the failure process of the frame meets the strong-column weak-beam criterion. Furthermore, cracking inter-story drift ratio and ultimate inter-story drift ratio both satisfy the limitation prescribed by the design code. Additionally, inter-story drift ratios at yielding and peak load stage provide reference data for Performance-Based Seismic Design (PBSD) approaches for composite RCS frames. An advantage over conventional reinforced concrete and steel moment frame systems is that the displacement ductility coefficient of the RCS frame system is much larger. To conclude, the test results prove that composite RCS frame systems perform satisfactorily under simulated earthquake action, which further validates the reliability of this innovative system. Based on the test result, some suggestions are presented for the design of composite RCS frame systems.

Cyclic testing of weak-axis column-tree connections with formation of plastic hinge at beam splice

  • Oh, Keunyeong;Chen, Liuyi;Hong, Sungbin;Yang, Yang;Lee, Kangmin
    • Earthquakes and Structures
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    • v.8 no.5
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    • pp.1039-1054
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    • 2015
  • The purpose of this study was to evaluate the seismic performance of weak-axis column-tree type connections used in steel moment frames. These connections are composed of a shop-welded and fieldbolted steel structure and can improve welding quality. On this basis, column-tree type connections are widely used in steel moment resisting frames in Korea and Japan. In this study, splices designed with a semirigid concept regarding the seismic performance of column-tree connections were experimentally evaluated. The structures can absorb energy in an inelastic state rather than the elastic state of the structures by the capacity design method. For this reason, the plastic hinge might be located at the splice connection at the weak-axis column-tree connection by reducing the splice plate thickness. The main variable was the distance from the edge of the column flange to the beam splice. CTY series specimens having column-tree connections with splice length of 600 mm and 900 mm were designed, respectively. For comparison with two specimens with the main variable, a base specimen with a weak-axis column-tree connection was fabricated and tested. The test results of three full-scale test specimens showed that the CTY series specimens successfully developed ductile behavior without brittle fracture until 5% story drift ratio. Although the base specimen reached a 5% story drift ratio, brittle fracture was detected at the backing bar near the beam-to-column connection. Comparing the energy dissipation capacity for each specimen, the CTY series specimens dissipated more energy than the base specimen.

A Study on Damage State Criteria based on Capacity Spectrum of Piloti-type RC Shear Wall Structures (필로티형 콘크리트 전단벽 구조물의 능력스펙트럼기반 손상도 기준에 대한 연구)

  • Hwang, Ji-Hyun;Park, Ki-Tae;Park, Tae-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.10
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    • pp.5199-5205
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    • 2013
  • Despite the increasing incidence of earthquakes in recent years, many of the existing buildings don't have appropriate seismic performance due to the deterioration or structural characteristics. In particular, a piloti-type RC shear wall structure, which is one of the building types in Korea, is highly vulnerable to earthquakes due to a great lack of shear function that can resist lateral force caused by the earthquake since the first floor is mostly soft story, and it is classified as weak story. In this regard, a study on the damage state criterion for the piloti-type RC shear wall structures was carried out. The capacity spectrum was calculated through the structural analysis by selecting typical type of buildings of shear wall systems, and damage state criterion was defined based on the shape of the capacity spectrum.

Shake-table responses of a low-rise RC building model having irregularities at first story

  • Lee, Han Seon;Jung, Dong Wook;Lee, Kyung Bo;Kim, Hee Cheul;Lee, Kihak
    • Structural Engineering and Mechanics
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    • v.40 no.4
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    • pp.517-539
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    • 2011
  • This paper presents the seismic responses of a 1:5-scale five-story reinforced concrete building model, which represents a residential apartment building that has a high irregularity of weak story, soft story, and torsion simultaneously at the ground story. The model was subjected to a series of uni- and bi-directional earthquake simulation tests. Analysis of the test results leads to the following conclusions: (1) The model survived the table excitations simulating the design earthquake with the PGA of 0.187 g without any significant damages, though it was not designed against earthquakes; (2) The fundamental mode was the torsion mode. The second and third orthogonal translational modes acted independently while the torsion mode showed a strong correlation with the predominant translational mode; (3) After a significant excursion into inelastic behavior, this correlation disappeared and the maximum torsion and torsion deformation remained almost constant regardless of the intensity of the two orthogonal excitations; And, (4) the lateral resistance and stiffness of the critical columns and wall increased or decreased significantly with the large variation of acting axial forces caused by the high bi-directional overturning moments and rocking phenomena under the bi-directional excitations.

Seismic performance evaluation of piloti-type low-rise RC apartment building (저층 RC 필로티형 집합 주택의 내진 성능 평가)

  • Lee, Han-Seon;Lee, Jeong-Jae
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.253-256
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    • 2008
  • The objective of this study is to evaluate the seismic weakness of existing nonseismic low-rise piloti-type apartment buildings which have the irregularities of weak story, soft story, and torsion simultaneously. A prototype 4-story RC building was selected, analyzed using linear dynamic procedure and finally evaluated according to the acceptance criteria of FEM356. This building satisfies the criteria.

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Seismic retrofit of framed structures using a steel frame assembly

  • Michael Adane;Seungho Chun;Jinkoo Kim
    • Steel and Composite Structures
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    • v.46 no.6
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    • pp.857-865
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    • 2023
  • This study aimed to develop a seismic retrofit technique using a steel frame which can be easily transported and assembled on site. This enables the retrofit steel frame to be easily attached to an existing structure minimizing the unwanted gap between the structure and the steel frame assembly. A one-story one-bay RC frame was tested with and without seismic retrofit using the proposed steel frame to verify the seismic retrofit effect of the proposed system, and an analysis model was developed in Opensees for seismic performance evaluation of a case study soft first-story model structure retrofitted with the developed steel frame assembly. Seismic performance of the model structure was also evaluated considering soil structure interaction effect. The experimental study confirmed that the proposed seismic retrofit system can be applied effectively to improve the seismic performance of framed structures. Time history analysis results of the model structure showed that the proposed steel frame assembly was effective in increasing the seismic load resisting capacity of the soft first-story structure. However more steel frame assemblies were required to satisfy the given performance limit state of the model structure located on weak soil due to the negative soil-structure interaction effect.

Retelling Silence, Rewriting Experience: Production and Reproduction of Anne Askew's Examinations

  • Hwang, Su-kyung
    • English & American cultural studies
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    • v.14 no.2
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    • pp.311-336
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    • 2014
  • The essay examines two different editions of Anne Askew's Examinations published in the sixteenth century: John Bale's the First Examination and the Latter Examination and John Foxe's Acts and Monuments, and argues that retelling and rewriting one's experience is the process of storytelling that necessitates the repetition and communication of the experience. The essay looks at the parts the sixteenth-century editors particularly rewrote or retold the original version, and discusses how Askew's story was retold, repeated, and communicated through various storytellers who delivered not only the original text but also the original experience toward larger audience. While attempting to interpret, analyze, and expand on the story she did not tell, or the story she could not tell, Bale and Foxe developed her personal and anecdotal story into a communal narrative to share. Bale wrote a weak woman's martyrology by adding his interpretation and analysis, showing the way for the readers to follow in understanding her enigmatic silence and gestures. On the other hand, Foxe made the story a more dramatic and more seamlessly flowing narrative of the heroic sacrifice of a martyr. Foxe filled the room left by Askew's silence with directly quoted conversations and the graphic that could help explain what was between the lines. Apart from the rewritings of the reformists, the essay focuses on the fact that the editing, rearranging, and reinterpreting process already started with Askew's own writing. Although Askew declares herself an objective recorder of the series of events, her writing is carefully constructed with complex ideological fractures and rhetorical tactics, and her experience is tailored to fit a particular purpose. Along with Bale's and Foxe's rewritings, Askew's story of a reading woman should be also read as an intentional and interpretative storytelling on her own experience.

A novel design method for improving collapse resistances of multi-story steel frames with unequal spans using steel braces

  • Zheng Tan;Wei-hui Zhong;Bao Meng;Shi-chao Duan;Hong-chen Wang;Xing-You Yao;Yu-hui Zheng
    • Steel and Composite Structures
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    • v.47 no.2
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    • pp.253-267
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    • 2023
  • The bearing capacities resisted by the two-bay beams of multi-story planar frames with unequal spans under column removal scenarios differ considerably owing to the asymmetric stress on the left and right beams connected to the failed column and cause the potential for beams with larger span-to-depth ratios to be unable to exert effectively, which is disadvantageous for resisting the vertical load in unequal-span frame structures. To address this problem, the structural measure of adding braces to the weak bays of multi-story unequal-span frames was proposed, with the objective of achieving a coordinated stress state in two-bay beams with unequal spans, thereby improving the collapse resistance of unequal-span frame structures. Before conducting the numerical simulation, the modeling methods were verified by previous experimental results of two multi-story planar frames with and without steel braces. Thereafter, the effects of the tensile and compressive braces on the collapse behavior of the frame structures were elucidated. Then, based on the mechanical action laws of the braces throughout the collapse process, a detailed design method for improving the collapse resistance of unequal-span frame structures was proposed. Finally, the proposed design method was verified by using sufficient example models, and the results demonstrated that the design method has good application prospects and high practical value.

A Study on the Box-office Performance of Films based on Computer Games - Forcusing on film Warcraft: The Beginning 2016 - (컴퓨터게임 원작 영화의 흥행성에 관한 연구 -영화 워크래프트 : 전쟁의 서막을 중심으로-)

  • Park, Chanik
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.13 no.4
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    • pp.193-199
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    • 2017
  • This study applied the scenario of the film "Warcraft: The Beginning, 2016" based on the world view and nonlinear story of online games to the basic requirements of a good story of five items. Based on this, it was found that the storyline of the film "Warcraft: The Beginning, 2016" was faithful to the game series with the same title, but weak for a film. This film did not satisfy any of the five requirements of a good scenario used for Hollywood production. Even before this film, many hit games were made into films, but box office hits are hard to find among them. As the game World of Warcraft was very famous worldwide, when it was made into a film, the film was expected to be a box office hit. However, it failed miserably at the box office. This is a result of failing to recognize that the characteristics of games that an individual leads the story are different from those of films that no interaction or choice can be made. It is necessary to understand that although games and films are the same in that they have narrative structures and visual stimulation graphics, they are totally different in the way they immerse people.