• Title/Summary/Keyword: vertical and torsional irregularities

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Study on the Seismic Performance for Low-rised RC Building with Vertical and Torsional Irregularities (수직비정형과 비틀림비정형을 동시에 가지는 저층 RC 건물의 내진성능에 관한 연구)

  • Choi, In-Hyuk;Baek, Eun-Rim;Lee, Sang-Ho
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.12
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    • pp.137-148
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    • 2019
  • Korean piloti-type buildings are comprised of pilotis in the first story and shear walls in the upper stories. This vertical irregularity causes excessive lateral plastic deformation on the first story while the upper stories stay elastic. Meanwhile, asymmetric position of structural components such as core walls and columns of RC piloti-type buildings tends to produce torsional irregularities of the structures. Korean Building Code(KBC2016) requires the special seismic load and torsional amplification factor to apply to the piloti-type buildings lower than six-story or 20m if it has vertical and torsional irregularities when the building corresponds to seismic design category C or D. Many Korean low-rised RC buildings fall into the class. Therefore, the special earthquake load and torsional amplification factor are often applied to a building simultaneously. However, it has not been studied enough how much influence each parameter has on buildings with vertical and torsional irregularities at the same time. The purpose of this study is to evaluate the effect of factor special seismic load and torsional amplification on seismic performance of irregular buildings. In this study, a damaged 4th story piloti-type building by the Pohang earthquake was selected and the earthquake response analysis was carried out with various seismic design methods by the KBC 2016. The effect of the design parameters on seismic performance was analyzed by the dynamic analysis of models with special seismic load and torsional amplification factor based on the selected building. It was concluded that the application of the torsional amplification factor to the reference model to which special seismic design was applied, does not significantly affect the seismic performance.

Dynamic Analysis of RC Piloti-Type Building Subjected to Earthquake Loads (지진하중이 작용하는 RC 필로티 건축물의 동적해석)

  • Kim, Ju-Won
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.34 no.3
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    • pp.121-128
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    • 2021
  • Piloti-type buildings in Korea are usually composed of lower frames and upper shear wall structures. Piloti-type buildings have been seriously damaged during earthquakes because of the construction of soft and weak stories. Piloti-type buildings with edge cores are two-way unsymmetric planes. This paper analyzed and obtained the dynamic response for structures modeled using a multistory two-way asymmetric system. The numerical results, obtained using the Newmark-β method, show the time-history responses and trends of maximum displacements and shear forces. The purpose of this study is to evaluate the effect of reinforcement on dynamic response when a shear wall or brace is reinforced in the corner opposite the piloti.

An Evaluation of Structural Performance of Reinforced Concrete Column Retrofitted with Grid Type Unit Details of Jacketing Method under Loading Patterns (격자형 유닛 상세를 가진 단면증설공법으로 보강된 철근콘크리트 기둥의 하중가력패턴에 따른 구조성능평가)

  • Moon, Hong Bi;Ro, Kyong Min;Lee, Young Hak
    • Journal of Korean Association for Spatial Structures
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    • v.22 no.2
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    • pp.29-37
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    • 2022
  • The collapse of reinforced concrete (RC) frame buildings is mainly caused by the failure of columns. To prevent brittle failure of RC column, numerous studies have been conducted on the seismic performance of strengthened RC columns. Concrete jacketing method, which is one of the retrofitting method of RC members, can enhance strength and stiffness of original RC column with enlarged section and provide uniformly distributed lateral load capacity throughout the structure. The experimental studies have been conducted by many researchers to analyze seismic performance of seismic strengthened RC column. However, structures which have plan and vertical irregularities shows torsional behavior, and therefore it causes large deformation on RC column when subjected to seismic load. Thus, test results from concentric cyclic loading can be overestimated comparing to eccentric cyclic test results, In this paper, two kinds of eccentric loading pattern was suggested to analyze structural performance of RC columns, which are strengthened by concrete jacketing method with new details in jacketed section. Based on the results, it is concluded that specimens strengthened with new concrete jacketing method increased 830% of maximum load, 150% of maximum displacement and changed the failure modes of non-strengthened RC columns.