Loading...

Generation of Endurance Time Functions Compatible with Near-Field Ground Motions

Zolfaghari, Mohammad | 2022

72 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 55676 (09)
  4. University: Sharif University of Technology
  5. Department: Civil Engineering
  6. Advisor(s): Esmail Pourestekanchi, Homayoon; Mashayekhi, Mohammad Reza
  7. Abstract:
  8. In the last few decades, the severe damages caused by near-field earthquakes have made researchers to investigate and study more of these types of earthquakes. The effect of forward directivity, which causes pulses with strong amplitude and long period in the velocity time history, is the main cause of severe damages of these types of earthquakes. The endurance time method is a dynamic analysis method in which the structure is subjected to increasing excitation functions. The purpose of this research is to investigate the effects of near-field earthquakes on structures and also to determine the accuracy of estimating responses caused by near-field earthquakes by the existing endurance time excitation functions. Then, if there is a significant estimation error, a new series of endurance time functions with more appropriate accuracy will be generated. The accuracy of the existing endurance time functions and the new series of functions, for a large number of single degree of freedom systems and several multi-story structures, in two specified return periods and based on the matching of the acceleration response spectra, is investigated. Then the source of the errors will be discussed. Also, the results of incremental dynamic analysis are compared with the results of endurance time analysis for multi-story structures. Wavelet transform and optimization methods have been used to generate new functions. The objective function is defined based on the difference of elastic response spectra of real earthquakes and endurance time functions. The results show the significant error of the existing endurance time functions in estimating the responses of pulse-like near-field earthquakes. But the new functions, despite being optimized based on elastic responses, showed good accuracy.

  9. Keywords:
  10. Endurance Time Method ; Optimization ; Incremental Dynamic Analysis ; Near-Field Earthquake ; Artificial Excitation Function Generation ; Seismic Damage

 Digital Object List

 Bookmark

No TOC