Lessons learned from the survey of damage to school buildings by the Mw = 8.4 Illapel earthquake (Chile, September 2015)
(English) The high seismic hazard present in the Chilean territory demands that essential buildings, such as educational facilities, be designed under rigorous structural performance criteria. However, recent events such as the Illapel earthquake, which occurred on September 15, 2015, and reached a...
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| Tipo de recurso: | tesis doctoral |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/439855 |
| Acceso en línea: | https://hdl.handle.net/2117/439855 https://dx.doi.org/10.5821/dissertation-2117-439855 |
| Access Level: | acceso abierto |
| Palabra clave: | Illapel Earthquake Earthquake damage School buildings Conceptual design Short-columns Seismic vulnerability Structural irregularities Seismic design deficiencies Educational infrastructure Reinforced concrete failure Plan asymmetry Site Effects and Geotechnical Characterization Nonlinear Dynamic analysis Nonlinear Numerical Modelling and Simulation Construction errors Nonstructural components 624 - Enginyeria civil i de la construcció en general 55 - Geologia. Meteorologia Àrees temàtiques de la UPC::Enginyeria civil |
| Sumario: | (English) The high seismic hazard present in the Chilean territory demands that essential buildings, such as educational facilities, be designed under rigorous structural performance criteria. However, recent events such as the Illapel earthquake, which occurred on September 15, 2015, and reached a magnitude of Mw = 8.4, have demonstrated that, despite advances in building codes, significant vulnerabilities persist in both the design and construction of this type of infrastructure. In this context, it becomes necessary to conduct a field study aimed at identifying the causes and mechanisms of structural damage. For this reason, a research team led by one of the supervisors of this doctoral thesis, affiliated with the Universidad Austral de Chile in Valdivia, traveled to the affected area to carry out a structural reconnaissance focused on the inspection of four schools located near the epicenter. A critical review of conceptual issues that may arise during the design stage of buildings is developed. This review includes seismic evaluation methods related to attenuation and wave propagation in the soil, as well as nonlinear numerical seismic analysis methodologies. Subsequently, the Illapel earthquake is contextualized through a historical overview of the seismicity in north-central Chile, and the characteristics of the mainshock that occurred on September 15, 2015, in Illapel, Coquimbo Region, Chile, are described. Then, a critical analysis is conducted of the structural and non-structural damage caused by the earthquake studied in the four educational facilities inspected during the field survey. For the building that presented the most severe damage, the San Rafael de Rozas School, a nonlinear dynamic analysis is performed to identify the causes of the observed damage level and its evolution over time during the event. To conduct this dynamic analysis, it was necessary to calibrate a site-specific seismic attenuation law (GMPE), since the Illapel earthquake displayed atypical propagation patterns, with higher accelerations recorded inland, away from the coastal edge. Consequently, the direct application of attenuation laws underestimates the actual seismic demand at the analysis site. For the validation of the numerical model, its results are compared with the observed damage patterns and with the frequencies obtained from the Operational Modal Analysis (OMA) carried out during the field inspection stage. The numerical results, therefore, allow for a clearer understanding of the building's seismic behavior and support the formulation of recommendations for seismic design and the evaluation of damaged structures. |
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