Comparative analysis between the Spanish and Portuguese seismic codes. Application to a border RC primary school

The Iberian Peninsula is close to the Eurasia-Africa plate boundary resulting in a considerable seismic hazard. In fact, the southwestern Iberian Peninsula is affected by far away earthquakes of long-return period with large-very large magnitude. A project named PERSISTAH (Projetos de Escolas Resilientes aos SISmos no Território do Algarve e de Huelva, in Portuguese) aims to cooperatively assess the seismic vulnerability of primary schools located in the Algarve (Portugal) and Huelva (Spain). Primary schools have been selected due to the considerable amount of similar buildings and their seismic vulnerability. In Portugal, the Decreto Lei 235/83 (RSAEEP) is mandatory while in Spain, the mandatory code is the Seismic Building Code (NCSE-02). In both countries, the Eurocode-8 (EC-8) is recommended. Despite the fact that both regions would be equally affected by an earthquake, both seismic codes are significantly different. This research compares the seismic action of Ayamonte (Huelva) and Vila Real de Santo António (Portugal). Both towns are very close and located at both sides of the border. Moreover, they share the same geology. This analysis has been applied considering a RC primary school building located in Huelva. To do so, the performance-based method has been used. The seismic action and the damage levels are compared and analysed. The results have shown considerable differences in the seismic actions designation, in the performance point values and in the damage levels. The values considered in the Portuguese code are significantly more unfavourable. An agreement between codes should be made for border regions.This work has been supported by the INTERREG-POCTEP Spain-Portugal programme and the European Regional Development Fund through the 0313_PERSISTAH_5_P project and the VI-PPI of the University of Seville by the granting of a scholarship. The grant provided by the Instituto Universitario de Arquitectura y Ciencias de la Construcción is acknowledged.info:eu-repo/semantics/publishedVersio

A cost-effective retrofitting technique for urm buildings based on steel encirclements in openings: a case study

A project named PERSISTAH is being developed to study the seismic vulnerability of primary schools in Huelva (Spain) and the Algarve (Portugal). This area has a moderate seismicity but this is affected by a nearby area where earthquakes of large magnitude (Mw≥6) and longreturn periods happen. The seismic vulnerability of URM (UnReinforced Masonry) buildings has been observed and analysed in the last decades. The seismic retrofitting of these buildings is required in order to improve their seismic behaviour. Many retrofitting techniques have been developed for that purpose, most of them very complicated and expensive. Therefore, these are not appropriate to retrofit a large number of buildings. This is especially relevant in areas of moderate seismicity where the cost-efficiency ratio must be carefully considered. The aim of this paper has been to develop a simple, effective and affordable technique to retrofit these buildings. These buildings are characterised by numerous openings which causes a great weakness in the URM walls. Then, a technique that consists in installing a steel encirclement or a grille in the openings of the walls has been proposed. This is a specific retrofitting technique for URM walls since this technique substantially improves the seismic capacity of these structures. To test the technique a case study is proposed. The building under study is a primary school located in Huelva and built in 1961. Results have shown that the capacity of the building is notably increased. Also, the performance point and the damage level of the structure are decreased.This work has been supported by the INTERREG-POCTEP Spain-Portugal programme and the European Regional Development Fund through the 0313_PERSISTAH_5_P project; PERSISTAH, Projetos de Escolas Resilientes aos Sismos no Território do Algarve e de Huelvainfo:eu-repo/semantics/publishedVersio

Fast seismic assessment of built urban areas with the accuracy of mechanical methods using a feedforward neural network

Capacity curves obtained from nonlinear static analyses are widely used to perform seismic assessments of structures as an alternative to dynamic analysis. This paper presents a novel ‘en masse’ method to assess the seismic vulnerability of urban areas swiftly and with the accuracy of mechanical methods. At the core of this methodology is the calculation of the capacity curves of low-rise reinforced concrete buildings using neural networks, where no modeling of the building is required. The curves are predicted with minimal error, needing only basic geometric and material parameters of the structures to be specified. As a first implementation, a typology of prismatic buildings is defined and a training set of more than 7000 structures generated. The capacity curves are calculated through push-over analysis using SAP2000. The results feature the prediction of 100-point curves in a single run of the network while maintaining a very low mean absolute error. This paper proposes a method that improves current seismic assessment tools by providing a fast and accurate calculation of the vulnerability of large sets of buildings in urban environments.info:eu-repo/semantics/publishedVersio

Projetos de escolas resilientes aos sismos no território do Algarve e de Huelva (PERSISTAH)

O projeto PERSISTAH propõe estudar o risco sísmico das escolas do primeiro ciclo do ensino básico localizadas nas regiões do Algarve (Portugal) e de Huelva (Espanha), dando assim cumprimento aos objetivos das Plataformas Nacionais para a Redução do Risco de Catástrofes (PNRRC) das Comissões Nacionais de Proteção Civil de Portugal e Espanha. O PERSISTAH tem como principais objetivos, melhorar o conhecimento mútuo das realidades das duas regiões, designadamente dos códigos sísmicos de cada país, e sobre as práticas construtivas regionais. Para tal foi criada uma ficha global de recolha de informação sobre as escolas do 1º ciclo (142 no Algarve e 139 em Huelva), que tendo em conta as especificidades das duas regiões. Foi desenvolvido um programa informático para a gestão da segurança sísmica das escolas, composto por três módulos: i) gestão da base de dados das escolas; ii) definição da ação sísmica a considerar; e iii) determinação do grau de dano e o School-Score de cada escola (um sistema de hierarquização do risco sísmico dos edifícios das escolas). Também foram desenvolvidos materiais pedagógicos para as crianças e professores. Os resultados obtidos com o programa informático desenvolvido mostram que os espectros de resposta estabelecidos pelos códigos sísmicos de Portugal e de Espanha são muito diferentes. Além disso, também se observaram diferenças muito significativas em função da lei de atenuação usada.info:eu-repo/semantics/publishedVersio

Seismic behaviour study of primary schools in Algarve and Huelva cities. Case study of three different building technologies

A project named PERSISTAH (Projetos de Escolas Resilientes aos SISmos no Território do Algarve e de Huelva, in Portuguese) is being developed. It aims to cooperatively assess the seismic vulnerability of primary schools of the Algarve (Portugal) and Huelva (Spain). Primary school buildings have been selected due to their low adult/child ratio and the fact that many of these buildings were constructed prior to the current seismic resistant codes. To determine the seismic behaviour of primary schools in both regions, this has been studied with building seismic performance analysis through the capacity-demand spectrum method. One of the main difficulties of the project has to do with the large amount of buildings to analyse. This paper is focused on obtaining and comparing the performance point of different types of buildings and different structural systems (reinforced concrete frames, unreinforced masonry walls and mixed). The goal is to be able to extrapolate the results from the buildings analyzed (type and structural system) to others where the information is not available. Different types and structural systems have been calculated and their seismic behaviours have been compared. The results show that the type and the structural system are outstanding for calculating the performance point and that an acceptable correlation can be inferred from similar types and structural systems. The comparison of the different structural systems for the same typology has shown that for the same shear force, the Reinforced Concrete (RC) frames buildings are able to get deformed significantly more than the Unreinforced Masonry (URM) walls

A comparative analysis between the Spanish and Portuguese seismic codes: application to a border RC Primary School

The Iberian Peninsula is close to the Eurasia-Africa plate boundary resulting in a considerable seismic hazard. In fact, the southwestern Iberian Peninsula is affected by far away earthquakes of long-return period with large-very large magnitude. A project named PERSISTAH (Projetos de Escolas Resilientes aos SISmos no Território do Algarve e de Huelva, in Portuguese) aims to cooperatively assess the seismic vulnerability of primary schools located in the Algarve (Portugal) and Huelva (Spain). Primary schools have been selected due to the considerable amount of similar buildings and their seismic vulnerability. In Portugal, the Decreto Lei 235/83 (RSAEEP) is mandatory while in Spain, the mandatory code is the Seismic Building Code (NCSE-02). In both countries, the Eurocode-8 (EC-8) is recommended. Despite the fact that both regions would be equally affected by an earthquake, both seismic codes are significantly different. This research compares the seismic action of Ayamonte (Huelva) and Vila Real de Santo António (Portugal). Both towns are very close and located at both sides of the border. Moreover, they share the same geology. This analysis has been applied considering a reinforced concrete (RC) primary school building located in Huelva. To do so, the performance-based method has been used. The seismic action and the damage levels are compared and analysed. The results have shown considerable differences in the seismic actions designation, in the performance point values and in the damage levels. The values considered in the Portuguese code are significantly more unfavourable. An agreement between codes should be made for border regions

A cost-effective retrofitting technique for URM buildings based on steel encirclements in openings: A case study

A project named PERSISTAH is being developed to study the seismic vulnerability of primary schools in Huelva (Spain) and the Algarve (Portugal). This area has a moderate seismicity but this is affected by a nearby area where earthquakes of large magnitude (Mw≥6) and longreturn periods happen. The seismic vulnerability of URM (UnReinforced Masonry) buildings has been observed and analysed in the last decades. The seismic retrofitting of these buildings is required in order to improve their seismic behaviour. Many retrofitting techniques have been developed for that purpose, most of them very complicated and expensive. Therefore, these are not appropriate to retrofit a large number of buildings. This is especially relevant in areas of moderate seismicity where the cost-efficiency ratio must be carefully considered. The aim of this paper has been to develop a simple, effective and affordable technique to retrofit these buildings. These buildings are characterised by numerous openings which causes a great weakness in the URM walls. Then, a technique that consists in installing a steel encirclement or a grille in the openings of the walls has been proposed. This is a specific retrofitting technique for URM walls since this technique substantially improves the seismic capacity of these structures. To test the technique a case study is proposed. The building under study is a primary school located in Huelva and built in 1961. Results have shown that the capacity of the building is notably increased. Also, the performance point and the damage level of the structure are decreased