DOI QR코드

DOI QR Code

Load Distribution of Sub-beam considering Slab Stiffness and Boundary Conditions

슬래브 강성 및 경계조건을 고려한 작은 보의 하중 분배

  • Kim, Yun Gon (Department of Architectural Engineering, Daegu University)
  • 김윤곤 (대구대학교 건축공학과)
  • Received : 2020.12.28
  • Accepted : 2021.02.15
  • Published : 2021.02.28

Abstract

A new floor load distribution method for slabs with sub-beam was proposed, taking into account slab stiffness. In the current 45 degree-based load distribution method, the load distribution ratio of sub-beam and girder (RB:RG) is the same (50:50). However, when considering the composite action with slab and boundary conditions, the ratio of sub-beam would be smaller than that of girder. In this study, floor load distribution ratio according to the relative stiffness of slab and sub-beam and boundary conditions was evaluated by finite element analysis including slabs. The load distribution of the slab was greater when increasing the relative stiffness of slab and sub-beam, and that of sub-beam decreased as greater as that of the slab. For conservative design approach, the reduced portion from the sub-beam due to would add the load distribution of girder rather than subtraction from total floor load. In practical modules- span length, beam geometry, etc., the ratio (RB:RG) can be adjusted up to 40:60 by reducing the stiffness of sub-beam obtained by performance based design.

Keywords

References

  1. ACI Committee 318. (1963). Building code requirements for reinforced concrete (ACI 318-63). Detroit, Mich: American Concrete Institute.
  2. Architectural Institute of Korea (2016). Korea Building Code and Commentary Ch. 10 Slab, p.293-318 (in Korean)
  3. Choi, S., Kim, S., Choi, Y., Lee, D., Kim, Y., & Ha, G. (2019). Reinforced Concrete Structure : Analysis and Design, Kimoondang, 384pp ISBN 9788962258431 (in Korean)
  4. MIDAS GEN User's Manual. ver 785. MIDAS IT; c2010
  5. Regan, P. E., & Yu, C. W. (1973). Limit state design of structural concrete. John Wiley & Sons.
  6. Shuraim, A. (2003). Applicability of Code Design Methods to RC Slabs on Secondary Beams. Part I: Mathematical Modeling, Journal of King Saud University - Engineering Sciences, Volume 15, Issue 2, p.181-196 https://doi.org/10.1016/S1018-3639(18)30770-0
  7. Szilard, R. (2004). Theories and Applications of Plate Analysis: Classical, Numerical and Engineering Methods. John Wiley & Sons., 1062pp
  8. Wight, J. K. (2016). Reinforced concrete: mechanics and design. Pearson, 1176pp