• Title/Summary/Keyword: Concrete Beams and Columns

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A Study on the Development of Construction Production Rates System for Estimating Proper Construction Expenses of Off-Site Construction (OSC) Based PC Structure Factory-Built Assembly (OSC기반 PC구조 공장제작 적정 공사비 산정을 위한 품셈체계 개발 연구)

  • Lee, Jeongwook;Lee, Hansoo;Lee, Chiho;Noh, Hyunseok
    • Korean Journal of Construction Engineering and Management
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    • v.23 no.6
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    • pp.89-100
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    • 2022
  • The development of the Construction Production Rates System for appropriate construction cost calculation has recently come to the fore as a means of invigorating OSC based PC structure which currently needs institutional frameworks. PC structure based construction expenses consist of the factory-built assembly, transportation and on-site installation. Recently, in the field of transportation and site installation, research on product structure development is being conducted, such as presenting the standard product calculation system reflecting the results of field survey for each subsidiary materials (Lee et al., 2021). On the other hand, there is no ongoing research on estimating construction expenses of Factory-built assembly. This study suggests Construction Production Rates System which can be used for PC subsidiary materials based Factory-built assembly cost estimations. For the research, work types for the construction procedures have been categorized, and the standard input manpower suitable for the corresponding work characteristics has been derived from analyzing the associated Construction Standard Production Rates for each work type. Also, as the research referred PC subsidiary materials (such as columns, beams, walls, and slab, as well as on-site installation) and the standard number of workforce based on work types, one can calculate direct labor cost, using what the research shows. In addition, it suggests that the size of individual subsidiary materials be the extra cost factor, by using the characteristics that productivity changes depending on the size(m3) of subsidiary materials. It is expected that the research can contribute to objectively verifying factory-built assembly cost through of PC structure, which currently relies on estimates.

Seismic Performance Assessment of a Composite Modular System Considering Stiffness of Connections (접합부 강성을 고려한 합성 모듈러 시스템의 내진 성능평가)

  • Choi, Young-Hoo;Lee, Ho-Chan;Kim, Jin-Koo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.2
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    • pp.105-114
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    • 2018
  • Modular system can be divided into two types based on the methods of resisting load. The one is the open-sided modular system composed of beams and columns. The other is the enclosed modular system composed of panels and studs. Of the Modular systems, the use of open-sided modular system is limited because it consists of closed member sections. In order to solve this problem, Choi et al.(2017) proposed a composite modular system with folded steel members filled with concrete. However, it was assumed in the previous study that the connections between modules are composed of rigid joint. Therefore it didn't identify the effect of connection behavior in structure. This study used finite element analysis to calculate stiffness of the connections in the proposed modular system. The linearization method presented in FEMA 440 is used for seismic performance assessment of structures, considering the connection stiffness computed in this study. The result of analysis shows that the capacity and story drift ratio obtained in the model considering stiffness of connection are less than those in the model not considering connection stiffness. Based on this observation, it is concluded that the stiffness of connection has a considerable effect on structural behavior.

Seismic Performance Assessment of a Composite Modular System Considering Stiffness of Connections (접합부 강성을 고려한 합성 모듈러 시스템의 내진 성능평가)

  • Choi, Young-Hoo;Lee, Ho-Chan;Kim, Jin-Koo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.1
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    • pp.9-18
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    • 2019
  • Modular system can be divided into two types based on the methods of resisting load. The one is the open-sided modular system composed of beams and columns. The other is the enclosed modular system composed of panels and studs. Of the Modular systems, the use of open-sided modular system is limited because it consists of closed member sections. In order to solve this problem, Choi et al.(2017) proposed a composite modular system with folded steel members filled with concrete. However, it was assumed in the previous study that the connections between modules are composed of rigid joint. Therefore it didn't identify the effect of connection behavior in structure. This study used finite element analysis to calculate stiffness of the connections in the proposed modular system. The linearization method presented in FEMA 440 is used for seismic performance assessment of structures, considering the connection stiffness computed in this study. The result of analysis shows that the capacity and story drift ratio obtained in the model considering stiffness of connection are less than those in the model not considering connection stiffness. Based on this observation, it is concluded that the stiffness of connection has a considerable effect on structural behavior.