| PaperNO | Paper / Abstract |
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SE11-025
14:20
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14:35
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Research of High-Strength Reinforced Concrete Structural System in Taiwan
With the rapid development of economy, a large number of people concentrated in metropolitan areas, and the urban construction land is gradually saturated. Therefore, the high-rise urban buildings can effectively solve the problem of insufficient urban new construction land or improve the urban renewal of most of the old and low-rise buildings. The urban renewal of the building will increase the public leisure space such as the green space around the building and enhance the quality of life in the city. The National Center for Research on Earthquake Engineering (NCREE) has completed the development of the "High-Strength Reinforced Concrete Structural System in Taiwan (New RC)" for 10 years since 2009. For comparing with the commonly used reinforced concrete structures, the strengths of steel and concrete materials are increased by about 1.65 to 2.5 times, respectively, which can expand the application range of domestic reinforced concrete construction materials. The research and development team of NCREE is willing to share the research and development experience of this high-strength reinforced concrete structural system, and fully assist the domestic construction industry to promote the construction of high-strength RC high-rise buildings. It is expected that high-strength RC structures will become a new trend of the domestic high-rise buildings.
Ker-Chun Lin, Kai-Ning Chi, Sheng-Jhih Jhuang
high-rise building, high-strength reinforced concrete, New RC
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SE11-027
14:35
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14:50
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RESILIENT CODE-ORIENTED SEISMIC DESIGN FOR DUCTILE REINFORCED CONCRETE FRAMES WITH HYSTERETIC FUSES
In this paper, the authors summarize the results of a parametric study devoted to evaluate, using static and dynamic nonlinear analyses, global design parameters for the resilient seismic design of ductile reinforced concrete (RC) frames with hysteretic energy dissipation devices mounted on chevron steel bracing. A capacity design procedure was used for the resilient seismic design of the frames under a performance-based design strategy, in order to clearly define the desired yielding sequence of structural elements for an ultimate fuse concept mechanism. From the results obtained in this study, stiffness balances were assessed to achieve suitable fuse mechanisms where the hysteretic devices yield first and develop their maximum local displacement ductility whereas elastic response is mostly obtained in the RC moment frame, with some incipient yielding is only formed at few beam ends. Nonlinear time-history analyses were conducted for acceleration records related to the design earthquake scenario. From the obtained results, it is confirmed that the proposed design procedure is reasonable to achieve resilient, fuse designs for an important range of the studied parameters and building heights when subjected to strong ground shaking.
Arturo Tena-Colunga
hysteretic energy dissipation devices, resilient seismic design, structural fuses
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G7-011
14:50
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15:05
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STUDY ON THE ACTUAL RESPONSES OF SEISMICALLY ISOLATED STRUCTURE IN THE HUALIEN TZUCHI MEDICAL CENTER
The HeXin Building, which is one of the hospital buildings in the TzuChi Medical Center located in Hualien City, is designed as a seismically base-isolated building. This structure is completed in February of 2005 and is installed by the real-time monitoring system to measure the structural responses. Four representative and significant earthquakes, which struck HeXin Building in April 30th of 2005, December 19th of 2009, October 31st of 2013, and February 6th of 2018, respectively, are recorded and discussed in this study. Owing to merely 2 km distance to the Milun Fault, most of earthquakes measured by free field stations near HeXin Building feature by the near-fault phenomenon. The reconnaissance and monitoring records are firstly exhibited in this study, and a numerical model is also established and modified according to the system identification result from the 2009 earthquake. The accuracy of this model is verified through dynamic time history analysis with the other three above-mentioned earthquakes. Then, the displacement responses of isolation system are compared through numerical analysis under two identical design-response-spectrum-compatible ground motions which are originated from earthquakes records with/out near fault phenomenon respectively. The result showed that even these two input ground motions possess similar response spectrum content, the one with near fault phenomenon still cause the isolation displacement 64% larger than another one. Therefore, it is noteworthy that designers should consider near-fault ground motions to ensure the conservative of seismically isolated design if the building site is located at and will be affected by any faults.
Kuo-Chun Chang, Chung-Han Yu, Shiang-Jung Wang, Cho-Yen Yang, Wang-Chuen Lin
actual seismic response, base isolation, near fault phenomenon, structural monitoring
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SE12-034
15:05
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15:20
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EFFECTS OF MASS IRREGULARITIES ON SEISMIC RESPONSES OF RC FRAMED STRUCTURES
Piloti buildings are the most common type used for multi-purpose residential buildings in dense metropolitan areas. Their lower stories can use for parking area and/or other service areas while the upper stories are usually utilized for residence houses. Such different usages between the lower and upper stories result in stiffness and mass irregularities which have been long recognized as a factor causing the devastating effect on the building collapse under strong ground motion. Before the comprehensive study on the effects of both irregularities on the seismic response of RC piloti framed structures, this study focuses on investigating the influence of mass irregularities. Three-dimensional mass-spring models were constructed to find out the seismic response of RC piloti frames throughout nonlinear time-history analyses. The seismic response amplifications due to the mass irregularities is analytically investigated. The nonlinear time-history analysis result shows that the seismic torsional response on the RC structural members in the piloti story are increased with the increase in the eccentricity and the degree of amplification of their seismic demands is significantly influenced by the direction of eccentricity.
Hyung-Joon Kim, Dong-Hyeon Shin, Hyun-Soo Jung
mass irregularity, nonlinear time-history analysis, RC piloti structures, seismic response amplification
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SE11-014
15:20
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15:35
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SHEAR BEHAVIOR OF STEEL REINFORCED ULTRA HIGH PERFORMANCE FIBER REINFORCED CONCRETE MEMBERS WITH HYBRID FIBERS
Current design codes require a dense array of steel reinforcement for shear-critical structural elements in earthquake-resistant structures, such as columns, walls, coupling beams, and beam-column joints. However, this leads to congested reinforcement in such elements during construction, which could cause extensively prolonged construction and reduced construction quality. This paper aims to investigate the potential of utilizing Ultra High Performance Fiber Reinforced Concrete with hybrid fibers to reduce shear reinforcement in shear-critical structural elements. A series of beams reinforced with longitudinal steel bars and various combinations of hybrid fibers were tested in a four-point loading setup. Two different shear spans to depth ratio were used to evaluate the effect of the hybridization in the shear response of the member. The test results showed that the presence of hybrid fibers enhanced the shear cracking stress, ultimate shear stress, and crack width controlled ability of the specimens compared to the monofiber beams. The results also indicated that the hybrid specimen with a less volume fraction of fibers could delay the appearance of cracking in the member.
Manuel Bermudez, Chung-Chan Hung
beams without shear reinforcement, hybrid fibers, shear strength, synergy
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