EVALUATION OF LATERAL LOAD PATTERN
IN PUSHOVER ANALYSIS
Armagan KORKMAZ1, Ali SARI2
1Visitor Researcher, Department of Civil Engineering, University of Texas at Austin, Austin,TX78712, PH: 512-232-9216; armagan@mail.utexas.edu
2Ph. D. Student, Department of Civil Engineering, University of Texas at Austin, Austin, TX 78712, PH: 512-232-9216; ali_sari@mail.utexas.edu
ABSTRACT
The objective of this study is to evaluate the performance of the frame structures or various load patterns and variety of natural periods by performing pushover and nonlinear dynamic time history analyses. The load distributions for pushover analyses are chosen as triangular, IBC (k=2) and rectangular. Four different framed structures are used, which are typical reinforced concrete (R\C) frame systems and have four different natural periods. Even though the nonlinear dynamic time history analysis is the best way to compute seismic demands FEMA-273 and ATC-40 proposes to use of nonlinear static procedure or pushover analysis. This paper is also intended to compare the results of pushover and nonlinear dynamic time history analyses. To evaluate the results from the pushover analyses for three load patterns and also four natural periods, nonlinear dynamic time history analyses are performed. Earthquake ground motions recorded at 50 stations during various earthquakes overall the world are used in the analyses. Pushover and nonlinear time history analyses results are compared to choose the best load distribution for specific natural period for this type of frame structure.
Keywords: Pushover analysis, nonlinear time history, load patterns, moment-resisting frame