- Volume 7 Issue 5
DOI QR Code
Lateral stiffness of reinforced concrete flat plates with steps under seismic loads
- Kim, Sanghee (Department of Architecture and Architectural Engineering, Seoul National University) ;
- Kang, Thomas H.K. (Department of Architecture and Architectural Engineering, Seoul National University) ;
- Kim, Jae-Yo (Department of Architectural Engineering, KwangWoon University) ;
- Park, Hong-Gun (Department of Architecture and Architectural Engineering, Seoul National University)
- Received : 2014.03.10
- Accepted : 2014.05.23
- Published : 2014.11.25
The purpose of this study is to propose a modification factor to reflect the lateral stiffness modification when a step is located in flat plates. Reinforced concrete slabs with steps have different structural characteristics that are demonstrated by a series of structural experiment and nonlinear analyses. The corner at the step is weak and flexible, and the associated rotational stiffness degradation at the corner of the step is identified through analyses of 6 types of models using a nonlinear finite element program. Then a systematic analysis of stiffness changes is performed using a linear finite element procedure along with rotational springs. The lateral stiffness of reinforced concrete flat plates with steps is mainly affected by the step length, location, thickness and height. Therefore, a single modification factor for each of these variables is obtained, while other variables are constrained. When multiple variables are considered, each single modification factor is multiplied by the other. Such a method is verified by a comparative analysis. Finally, a complex modification factor can be applied to the existing effective slab width.
lateral stiffness;slab with step;flat plate, modification factor;effective slab width method
Supported by : National Research Foundation of Korea (NRF)
- ABAQUS (2012), "4.5.2 Damaged Plasticity Model for Concrete and Other Quasi-Brittle Materials", ABAQUS Theory Manual, Version 6.12, Dassault Systèmes Simulia Corp., Providence, RI, USA.
- American Concrete Institute (ACI) (2012), "Detailing corner: steps in beams", Concrete Int., 34(6), 41-44.
- Architectural Institute of Korea (AIK) (2009), Korean Building Code and Commentary 2009, Kimoondang Publishing Company, Korea.
- Ellouse, A., Ouezdou, M.B. and Karray, M.A. (2013), "Experimental Study of Steel Fiber Concrete Slabs Part I: Behavior under Uniformly Distributed Loads", Int. J. Concrete Struct. Mater., 4(2), 181-196.
- George, S.J. and Tian, Y. (2012), "Structural Performance of Reinforced Concrete Flat Plate Buildings Subjected to Fire", Int. J. Concrete Struct. Mater., 6(2), 111-121. https://doi.org/10.1007/s40069-012-0011-2
- Grossman, J.S. (1997), "Verification of Proposed Design Methodologies for Effective Width of Slabs in Slab-Column Frame", ACI Struct. J., 94(2), 181-196.
- Kaynia, A.M. (2012), "Dynamic response of pile foundations with flexible slabs", Earthq. Struct., 3(3), 495-506. https://doi.org/10.12989/eas.2012.3.3_4.495
- Korea Concrete Institute (KCI) (2012), Concrete Design Code, Kimoondang Publishing Company, Korea.
- Korea Land & Housing Corporation (KLHC), Bureau of Mechanical Design (2012), Establishment of Design Standard for Drainage Layout at the Floor for the Noise Reduction in the Bathroom (Proposal), Report of Korea Land & Housing Corporation, Korea.
- Lu, X., Urukap, T.H., Li, S. and Lin, F. (2012), "Seismic behavior of interior RC beam-column joints with additional bars under cyclic loading", Earthq. Struct., 3(1), 37-57. https://doi.org/10.12989/eas.2012.3.1.037
- Song, J.K., Kim, J., Song, H.B. and Song, J.W. (2012), "Effective punching shear and moment capacity of flat plate-column connection with shear reinforcements for lateral loading", Int J. Concrete Struct. Mater., 6(1), 19-29. https://doi.org/10.1007/s40069-012-0002-3