In many seismically active regions of the world there are large numbers of masonry buildings. Most of these buildings have not been designed for seismic loads. Recent earthquakes have shown that many of these building...In many seismically active regions of the world there are large numbers of masonry buildings. Most of these buildings have not been designed for seismic loads. Recent earthquakes have shown that many of these buildings are seismically vulnerable and should be considered for retrofitting. Different conventional and unconventional retrofitting techniques are available to increase the strength and/or ductility of unreinforced masonry （URM） walls. This paper reviews and discusses seismic retrofitting of masonry walls with emphasis on the conventional techniques. Retrofitting procedures are discussed with regard to a case study： a stone masonry building in lrpinia region, damaged by the 1980 earthquake. The interventions are evaluated by means of finite elements with a macroelement obtained with a homogenization technique. Linear and nonlinear procedures are compared, and peculiarities of each procedure are shown.展开更多
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 ...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.展开更多
The geoelectrical resistivity and seismic refraction surveys which were used in this study on the test site, delivered a detailed image of the near-surface conditions in generally very good. Electrical resistivity and...The geoelectrical resistivity and seismic refraction surveys which were used in this study on the test site, delivered a detailed image of the near-surface conditions in generally very good. Electrical resistivity and seismic refraction analysis proved that a combination of these integrated study of the physical environmental data provided a reasonable compromise between measurement time and image resolution. Quantitative interpretation of the resistivity and seismic models based on soil's parameters determined using laboratory practices and field survey could reproduce the range of resistivity and seismic values found on the site very well. The model explains the ambiguity in between resistivity and clayey sands found on the site and predict the dominant role of water saturation. Geophysical methods are used in this research in purpose to determine the internal structure of a soil mass. Various geophysical methods and their merits for imaging subsurface structures and condition are discussed. Seismic methods are often the most suitable because the measurements depend on the mechanical properties which are also important in the mechanical calculation of soil's behaviour analysis. Other geophysical method, such as geoelectric resistivity, is useful to determine the internal structure, but require a correlation of found boundaries with mechanical properties. This research was conducted to investigate the subsurface structures and conditions through geotechnical engineering properties and its geophysical characteristics. The computation analysis is used in this research in purpose to investigate clayey sand soil's behaviour. Electrical resistivity test and engineering laboratory practices such as soil strength test, liquid limit test, plastic limit test and grain size distribution test was also carried out to investigate clayey sand soil behaviour in Batu Uban, Penang area during monitoring period.展开更多
The use of steel structures in the developing countries is limited in spite of its better performance in the case of seismic events due to its high ductility. Although steel structures behave well under seismic excita...The use of steel structures in the developing countries is limited in spite of its better performance in the case of seismic events due to its high ductility. Although steel structures behave well under seismic excitation, nevertheless the use of structural steel is limiting these days. This paper aims to address various parameters related to the capacity design approach involved in the seismic design of conventional steel structures. Few cases of the early steel structures construction such as bridges in Pakistan are briefly described. Philosophies based on the capacity design approach and the importance of conventional steel lateral load resisting systems with their global mechanisms are provided. The design procedures of Eurocode 8 for Steel Moment resisting frames, Concentric cross braced frames and Eccentric braced frames are given and illustrated. It is believed that the paper will contribute and will be helpful for the designers, researchers and academicians involve in the study of lateral load resisting systems for incorporating in the design process. Since synopsis tables are provided, therefore this will allow a clear understanding of the capacity design approach for different lateral load resisting systems.展开更多
文摘In many seismically active regions of the world there are large numbers of masonry buildings. Most of these buildings have not been designed for seismic loads. Recent earthquakes have shown that many of these buildings are seismically vulnerable and should be considered for retrofitting. Different conventional and unconventional retrofitting techniques are available to increase the strength and/or ductility of unreinforced masonry （URM） walls. This paper reviews and discusses seismic retrofitting of masonry walls with emphasis on the conventional techniques. Retrofitting procedures are discussed with regard to a case study： a stone masonry building in lrpinia region, damaged by the 1980 earthquake. The interventions are evaluated by means of finite elements with a macroelement obtained with a homogenization technique. Linear and nonlinear procedures are compared, and peculiarities of each procedure are shown.
基金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 and Ciencias de la Construcción is acknowledged.
文摘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.
文摘The geoelectrical resistivity and seismic refraction surveys which were used in this study on the test site, delivered a detailed image of the near-surface conditions in generally very good. Electrical resistivity and seismic refraction analysis proved that a combination of these integrated study of the physical environmental data provided a reasonable compromise between measurement time and image resolution. Quantitative interpretation of the resistivity and seismic models based on soil's parameters determined using laboratory practices and field survey could reproduce the range of resistivity and seismic values found on the site very well. The model explains the ambiguity in between resistivity and clayey sands found on the site and predict the dominant role of water saturation. Geophysical methods are used in this research in purpose to determine the internal structure of a soil mass. Various geophysical methods and their merits for imaging subsurface structures and condition are discussed. Seismic methods are often the most suitable because the measurements depend on the mechanical properties which are also important in the mechanical calculation of soil's behaviour analysis. Other geophysical method, such as geoelectric resistivity, is useful to determine the internal structure, but require a correlation of found boundaries with mechanical properties. This research was conducted to investigate the subsurface structures and conditions through geotechnical engineering properties and its geophysical characteristics. The computation analysis is used in this research in purpose to investigate clayey sand soil's behaviour. Electrical resistivity test and engineering laboratory practices such as soil strength test, liquid limit test, plastic limit test and grain size distribution test was also carried out to investigate clayey sand soil behaviour in Batu Uban, Penang area during monitoring period.
文摘The use of steel structures in the developing countries is limited in spite of its better performance in the case of seismic events due to its high ductility. Although steel structures behave well under seismic excitation, nevertheless the use of structural steel is limiting these days. This paper aims to address various parameters related to the capacity design approach involved in the seismic design of conventional steel structures. Few cases of the early steel structures construction such as bridges in Pakistan are briefly described. Philosophies based on the capacity design approach and the importance of conventional steel lateral load resisting systems with their global mechanisms are provided. The design procedures of Eurocode 8 for Steel Moment resisting frames, Concentric cross braced frames and Eccentric braced frames are given and illustrated. It is believed that the paper will contribute and will be helpful for the designers, researchers and academicians involve in the study of lateral load resisting systems for incorporating in the design process. Since synopsis tables are provided, therefore this will allow a clear understanding of the capacity design approach for different lateral load resisting systems.
