A Spanish-Portuguese team, made up of experts from the Universities of Sevilla and Algarve, has developed a procedure that analyzes and reduces the vulnerability of school buildings to seismic damage. The focus of the work is on primary school buildings constructed in Huelva and the Algarve during the 1970s.
Experts from the Universities of Seville and Algarve (Portugal) have created a system to assess and reinforce schools against earthquakes. Through a set of indicators, the method offers the best solution to make these buildings more resistant, based on the principles of efficiency, cost, and architectural impact. The formula can be applied to other types of buildings, such as houses, high schools, or hospitals.
Using a software application, these experts analyze the behavior of the buildings according to seismic regulations. This generates data to understand the structural response and the level of damage the building would suffer during an earthquake. From there, the method evaluates how the school’s behavior could be improved using different structural reinforcement systems.
This information is assessed together with cost and architectural impact indicators to identify the best alternative. “Many centers could be subject to structural reinforcement, so part of the work has been to screen which construction solutions best fit our technology, are more economical, and respect the building’s design to keep it functional,” notes Antonio Morales, co-author of the work and head of the PERSISTAH project at the University of Seville, funded by the INTERREG-POCTEP program, which supports the research.
The study uses schools built in Huelva and the Algarve as a reference. “Most of these schools were constructed during the 1970s. Therefore, seismic requirements were not restrictive, and in most cases, the design only considered gravitational loads,” explains the lead author María Victoria Requena García de la Cruz, a researcher at the University of Seville, to Fundación Descubre.
The method has been successfully applied in a school in Huelva, and the results, along with the various stages of the system developed by this team, have been published in the journal PLOS ONE under the title: “An index-based method for evaluating seismic retrofitting techniques. Application to a reinforced concrete primary school in Huelva.”
Area of High Seismic Activity
The regions of Huelva and the Algarve are characterized by significant earthquake activity, as is the case with other parts of Andalusia identified in Spain’s seismic hazard map. This is due to their proximity to the Gibraltar-Azores fault, where the Eurasian and African tectonic plates meet. Exposure to seismic tremors can be worsened depending on the soil type where the building is located. “In the case of Huelva, being near the coast and marshland, the presence of soft soils is notable, which has a multiplier effect on the impact of the earthquake,” says María Victoria Requena.
Additionally, primary schools in both regions share common seismic vulnerabilities. The oldest ones (from the 1960s) follow a load-bearing wall system, with a high percentage of openings in the walls and low-quality materials. The rest are based on shorter-than-usual pillars and reinforced concrete beams. The ground floors are weaker as they lack enclosure and do not rest directly on the ground but on an insulating layer (known as a sanitary slab)
References:
Requena-García-Cruz MV, Morales-Esteban A, Durand-Neyra P, Estêväo J. ‘An index-based method for evaluating seismic retrofitting techniques. Application to a reinforced concrete primary school in Huelva’ PLOS ONE. DOI: 10.1371/journal.pone.0215120.