Linear Time-History Analysis as EC8-compliant Design Method for Simplified Performance-Based Earthquake Engineering Assessment

  • Luca Lombardi

Student thesis: Doctoral ThesisDoctor of Philosophy (PhD)

Abstract

The routine analysis approach for seismic design of buildings is generally linear-elastic and carried out according to “force-based” approaches. These approaches are based on approximate evaluation of the dynamic structural response. Linear Time-History Analysis (LTHA) is not new in earthquake engineering but many codes, including Eurocode 8 (EC8), do not mention explicitly LTHA among the possible methods of analysis for design. LTHA can represent a simplified tool for engineers avoiding the complexity of nonlinear models for advanced analyses as well as approximate assumptions on the evaluation of the dynamic structural response. Eurocodes are currently under review for a second-generation release, for this reason, this research aims to deal with the gap in the code, related to the possibility of designing buildings through LTHA. A “force-based” EC8-compliant LTHA design framework is proposed and presented for the design of an archetype 12-storey Reinforced-Concrete (RC) Moment-Resisting-Frame (MRF) building located in medium-high seismicity area. Aspects such as: interaction between local force components, the estimation of P-Delta amplification factor, the damping modelling and, finally, the implementation of the behaviour factor are investigated. The novel aspect which characterises this research is the possibility to account for the seismic input variability, suiting design purposes, without losing the opportunity to capture specific response features such as pulse-like effects. The possibility to have a direct comparison between linear response at design stage and nonlinear response within a Performance-Based Earthquake Engineering (PBEE) assessment using the same suite of ground motions is herein investigated in order to propose a suitable approach for the derivation of fragility curves at design stage aimed at comparing and ranking different design solutions. The aim of this work is to open up new opportunities for designers towards a performance-based approach implemented at design stage avoiding the development of a nonlinear model to compare different design options.
Date of Award25 Jun 2019
Original languageEnglish
Awarding Institution
  • The University of Bristol
SupervisorFlavia De Luca (Supervisor) & John H G Macdonald (Supervisor)

Keywords

  • Time History Analysis
  • Performance Based Earthquake Engineering
  • Ground Motion Selection
  • Eurocode 8
  • Unacceptable Case
  • Fragility Curve
  • Near Field
  • Far Field
  • Pulse like
  • Loss Assessment

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