فهرست مطالب s. el janous

Ensuring seismic resilience in earthquake-prone regions is imperative for structural safety. Fiber-Reinforced Concrete (FRC) columns hold promise for enhancing structural performance under seismic conditions. This study seeks to comprehensively evaluate their seismic behavior. The primary objective of this research is to assess and compare the seismic performance of various FRC column types, including polypropylene fibers (PFRC), steel fibers (SFRC), and hybrid combinations (HyFRC), in contrast to conventional reinforced concrete (RC) columns. To achieve this, the study employs eXtended Finite Element Method combined with Concrete Damage Plasticity (XFEM-CDP) in Abaqus to scrutinize static and dynamic responses. The nonlinear static pushover analysis unveiled a notable improvement in seismic resistance across all FRC types when compared to RC columns. Incremental dynamic analyses (IDA) are conducted using the selected suite of 10 near fault as-recorded ground motions to evaluate the inelastic seismic responses of different FRC bridge columns. XFEM-CDP simulations in Abaqus captured multiple aspects of FRC columns, such as concrete cracking, loss of stiffness and plastic behavior. Seismic fragility analysis of these FRC columns is conducted considering four damage states: a) longitudinal steel yielding, b) core concrete crushing, c) steel bar buckling, and d) longitudinal steel bar fracture. The results indicated that HyFRC columns exhibit the lowest damage vulnerability compared to PFRC and SFRC variants.

In this study, we present an investigation into the seismic vulnerability assessment of medium-rise reinforced concrete structures featuring vertical geometric irregularity (setback). We considered the effects of the percentage and location of the setback along the height of the building, as well as the impact of changing site classes. Additionally, we incorporated the effects of soil-structure interaction into the nonlinear response of the building. In the first part, we investigated the influence of the aforementioned parameters on the seismic response of a structure through nonlinear static analyses. We analyzed the capacity curves and the development of plastic hinges in the structural elements. In the second part, we analyzed the seismic fragility of building frames using a probabilistic study approach. We developed fragility curves to assess the vulnerability of the structures.In conclusion, the obtained results highlight the fundamental importance of considering  structural irregularities as well as the impact of different site classes on the seismic vulnerability of buildings.