P-Delta Effect on The Dynamic Seismic Response of High Rise Buildings

In this study, main attention was focused on the effects of the second-order geometric nonlinearity of P-Delta and concrete cracking on the modal analyses and on the static and dynamic seismic response of high rise reinforced concrete buildings. Different reinforced concrete building models including regular and irregular layout with different heights up to 50 stories were analyzed. Various intensities for earthquake ground motion forces including minor earthquake up to a moderate or strong earthquake with different site classes were covered in this study. Also, static and dynamic analysis procedures were considered for the seismic response analysis including Equivalent Lateral Force and Response Spectrum Analysis procedures. ETABS software (version 16.0.3) has been used for numerical analyses of all case studies covered in this study. Results of analyses revealed that time periods of vibration elongated when P-Delta and concrete cracking effects accounted for in the analyses. A maximum increase of about 40% and 15% in the fundamental time periods of vibration was observed due to cracking of concrete and P-Delta effects, respectively.