A Modified Equivalent Frame Model for Plat Plate Slabs Under Lateral Loads

수평하중을 받는 플랫 플레이트 슬래브 해석을 위한 수정된 등가골조모델

  • Han Sang-Whan (Dept of Architectural Engineering, Hanyang University) ;
  • Park Young-Mi (Dept of Architectural Engineering, Hanyang University)
  • Published : 2005.06.01


This study is to propose a modified equivalent frame model for flat plate slabs under lateral loads. ACI 318 (2002) allows equivalent frame methods to conduct two-way slab system analysis subjected to gravity loads as well as lateral loads. Since the equivalent frame method in the ACI 318 (2002) has been developed base on the behavior of two-way system for gravity loads, and nay not predict the behavior of flat plate slabs under lateral loads with good precision. This study develops a modified equivalent frame model which can give more precise answer for flat plate slabs under lateral loads. This model reflects the actual force transfer mechanism among the components of flat plate slab system, which are slabs, columns and torsional members, more accurately under lateral loads than existing equivalent frame models. The accuracy of this model is verified by comparing the analysis results using the proposed model with the results of finite element analysis. The analysis results of other existing models are included in the comparison. For this purpose, 2 story building having 3 spans in both directions is considered. Analytical results show that the modified equivalent frame model produces comparable drift and slab internal moments with those obtained from finite element analysis.


  1. ACI, ACI 318-02 Building Code Requirements for Structural Concrete and Carmmentary, ACI, USA, 2002
  2. Pecknold, D. A., 'Slab Effective Width for Equivalent Frame Analysis', ACI Journal, April 1975, pp.135-137
  3. Allen, F. H. and Dravell, P. LeP. 'Lateral Load Equivalent Frame', ACI Journal, Jul. 1977, pp.294-299
  4. Banchik, C. A., 'Effective Beam Width Coefficients for Equivalent Frame Analysis of Flat-Plate Structures', MD thesis, University of California at Berkeley, Cali. May 1987, 56pp
  5. Luo, Y. H. and Durrani, A. J., 'Equivalent Beam Model for Flat-Slab Buildings-Part I: Interior Connection', ACI Structural Journal, Jan.-Feb. 1995, pp.115-124
  6. Luo, Y. H. and Durrani, A. J., 'Equivalent Beam Model for Flat-Slab Buildings-Part II: Exterior Connection', ACI Structural Journal, Mar.-Apr. 1995, pp.250-257
  7. Corly, W. G. and Jirsa, J. O., 'Equivalent Frame Analysis for Slab Design', ACI Journal, Nov. 1970, pp.875-884
  8. Vanderbilt, M. D., 'Equivalent Frame Analysis for Lateral Loads', Proceedings, ASCE, Journal of the Structural Division, Vol.105, ST10, Oct, 1979, pp.1981-1998
  9. Vanderbilt, M. D. and Corley, W. G., 'Frame Analysis for Concrete Buildings', Concrete International : Design & Construction, Vol.5, No.12, Dec. 1983. pp.33-43
  10. Cano, M. T. and Klingner, R. E., 'Comparison of Analysis Procedures for Two-Way Slabs', ACI Journal, Nov.-Dec. 1988, pp.597-608
  11. Hwang, S. J. and Moehle, J. P., 'Models for Laterally Loaded Slab-Column Frames,' ACI Journal, Mar. 2000, pp.345-351
  12. Wilson, E. L. Holling, J. P., and Dovey, H. H., 'ETABS Three-Dimensional Analysis of Building systems (Extended Version)', computer programe, National Information Service in Earthquake Engineering, Berkeley, 1977
  13. Computers and Structures, Inc. 'SAP2000 Integrated Finite Element Analysis and Design of Structures', Berkeley, California, USA, 1996
  14. Ian. N. Robertson, 'Analysis of Flat Slab Structures Subjected to Combined Lateral and Gravity Loads', ACI Journal, Nov. 1997, pp.723-729