Loading...

Proposing Appropriate Lateral Load Pattern for 3-D Pushover Analysis of Unsymmetric-Plan Building Structures

Asadollahi, Parisa | 2012

536 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 44012 (09)
  4. University: Sharif University of Technology
  5. Department: Civil Engineering
  6. Advisor(s): Rahimzadeh Rofooei, Fayyaz
  7. Abstract:
  8. Recent studies in the area of damage assessment of structures under severe earthquakes have shown that plan asymmetry of structures have considerable effects on the severity of the induced damages. In these cases, structure enters into its nonlinear behaviour, and both structural and nonstructural elements sustain large forces and deformations. Nowadays, due to the complication of nonlinear dynamic analyses in estimating these forces and deformations in case of seismic ground motion, the use of nonlinear static analysis methods has increased. These procedures expose the structures to monotonically increasing lateral forces with an invariant height-wise distribution until a predetermined target displacement at control node is reached. The conventional nonlinear static procedures have some liabilities in predicting the inelastic seismic demands of unsymmetric medium-rise and high-rise buildings in which higher mode contributions and torsional effects are significant. The purpose of this research is to develop and verify appropriate load pattern for predicting seismic responses of buildings with unsymmetric plan such as story displacements, story drifts and hinge plastic rotations under nonlinear static procedure. In the proposed method, the final seismic responses are determined by enveloping the results of three pushover analyses. For evaluating the proposed method, unsymmetric plan systems with different degrees of lateral-torsional coupling, including torsionally-flexible systems, torsionally-similarly-stiff systems and torsionally-stiff systems are considered. The different eccentricities which are selected to be along one axis are equal to 10% and 15% of the plan dimension. These models are subjected to seven uni-direction far-field earthquake records. To verify the proposed procedure, comparisons have been made between the results of proposed methods with exact values obtained by nonlinear time history analysis and estimates of modal pushover analysis. Story displacements, story drifts and hinge plastic rotations have been taken into consideration as criteria to control the proposed procedure. It is demonstrated that the proposed method can estimate the story displacements, story drifts and hinge plastic rotations of symmetric and one-way unsymmetric-plan medium-rise buildings to a reasonable degree
  9. Keywords:
  10. Nonlinear Static Analysis ; Nonlinear Dynamic Analysis ; Unsymmetric-Plan Buildings ; Modal Pushover

 Digital Object List

 Bookmark

No TOC