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The research aims to advance the field of seismic design by examining the structural behaviour of reinforced concrete (RC) structures in accordance with the first and second generations of Eurocode 8, mainly focusing on the vertical irregularity criteria. The document integrates substantial theoretical, comparative, and numerical research on seismic codes, vertical irregularity criteria comparison and structural behaviour under seismic actions.
The introduction outlines the thesis's scope and objectives, highlighting the need to advance seismic-resistant design methodologies in response to the continual evolution of building codes, with a specific focus on structural vertical irregularities. It contextualizes the critical role of seismic structural engineering in mitigating earthquake-induced damage to infrastructure.
The thesis conducts a review of international seismic design standards. It compares them, mainly focusing on vertical irregularity criteria and the regularity classification impact in the seismic behaviour factor. It was presented the lessons learned from experiences of structural damages in seismic events associated with structural irregularities in China, Italy, Spain, Nepal, Mexico and Turkey. Additionally, this section compared the vertical irregularity criteria through several seismic codes, including those from Europe, Brazil, Mexico, Chile, USA and New Zealand.
The chapters dedicated to numerical studies present a comparative evaluation of the effects of the first- and second-generation vertical irregularity criteria outlined in Eurocode 8 on the seismic performance of Ductility Class Medium (DCM) RC moment-resisting frames and shear wall systems. It evaluates the impact of imposed vertical irregularity due to increasing height, column cross-section, inter-storey mass and resistance shift. Furthermore, it was assessed the combined influence of irregularity in elevation and corrosion in seismic response. Through comprehensive numerical simulations and structural analyses, the study elucidates the extent to which these parameters influence the overall structural integrity and safety of buildings subjected to seismic loading.
From those contributions, an assessment was conducted to examine the changes in the methodology for calculating the behaviour factor between the first and second generations of Eurocode 8 as applied to the developed structural models. The main purpose of this chapter is to evaluate different levels of vertical irregularity and propose the correspondent intermediate corrections levels of behaviour factor. The findings highlight the differential impact of vertical irregularity on seismic response and support the proposed amendments for inclusion in the draft of the second generation of Eurocode 8.
Finally, the document concludes by synthesizing the research findings and outlining prospective directions for the continued development of seismic design standards and practices. It identifies key areas where further investigation is warranted to enhance the understanding and assessment of structural irregularities in RC buildings, with the aim of improving their seismic performance. Emphasis is placed on the necessity for ongoing innovation and adaptability within the field of structural engineering to address the evolving challenges presented by seismic hazards.