Optimal seismic retrofitting techniques for URM school buildings located in the southwestern Iberian peninsula

Abstract

This paper aims to study different seismic retrofitting techniques to test the reduction of the seismic vulnerability of unreinforced masonry buildings. Three techniques have been considered in a case study: adding steel or carbon fibre reinforced polymer grids in the walls and steel encirclements in the openings. The performance-based method has been used to that purpose. Nonlinear static analyses have been performed to obtain the capacity and fragility curves, the performance point and the damage level states. Moreover, an analysis of the cost-benefit ratio has been carried out. Results have shown that the three techniques have produced considerable improvements. The addition of encirclements has reduced the deformation resulting in a slight increase of the structure’s stiffness. Adding steel grids has produced the maximum peak strength increase while adding polymer grids has produced the largest ultimate displacements. Adding encirclement has had the best cost-benefit ratio.

Specific seismic retrofitting of a compact reinforced concrete building with X-bracings and steel jackets. Application to a primary school in Huelva

“…The works described in this paper are framed under the European project PERSISTAH (Projetos de Escolas Resilientes aos SISmos no Território do Algarve e de Huelva, in Portuguese), cooperatively developed between Spain and Portugal [8,9]. The main goal of the project is to assess the seismic vulnerability of primary schools located in the Algarve (Portugal) and Huelva (Spain).…”

“…The yield strength (F y � ), which represents the ultimate strength PLOS ONE of the idealised system, is equal to the base shear force at the formation of the plastic mechanism. In this sense, the yield displacement of the idealised SDOF system (d y � ) is given by the equation (9). Where d � m is the displacement and E � m is the deformation energy leading to the formation of the plastic mechanism (A).…”

Rehabilitación sísmica estructural de colegios de educación primaria

“…Además, debido a sus dimensiones (figuras 82 y 83), se adapta a las condiciones y a la escala de intervención propuesta en el proyecto. En dicho proyecto se han aplicado las técnicas de refuerzo sísmico analizadas en el estudio sobre el refuerzo sísmico de un edificio escolar de muros de carga (Segovia-Verjel et al, 2019), realizado en el proyecto de investigación. En este caso se han aplicado dos métodos de refuerzos: la aplicación de una malla de acero en la cara exterior del muro, y el refuerzo de los huecos mediante un recercado con el aumento de la cuantía de armado de redondos de acero.…”

A Discrete Macro Element Method for Modelling Ductile Steel Frames around the Openings of URM Buildings as Low Impact Retrofitting Strategy

“…The influence of the steel-profile crosssection, the position of the opening within the wall, and the degree of connection between the steel uprights and the masonry are evaluated. Segovia-Verjel et al [5,6] suggested a cost-effective retrofitting technique for URM buildings based on steel encirclements in existing openings. They evaluated the influence of the steel encirclements by using a frame modelling approach for the masonry building, without considering the complex interaction between the masonry and the frame that can modify the failure mechanism of the combined system and introduces an additional confinement effect both on the piers and the spandrels.…”

“…The numerical modelling of this strengthening technique is far from being easy and rigorously requires complex nonlinear FEM simulations, such as those adopted for simulating experimental results on prototypes in [4,7]. Oversimplified approaches, such those based on equivalent frame modelling, as those adopted in [5,6], are not able to provide a reliable simulation of the interaction between the steel frame and the masonry wall. It is worth noting that the introduction of an interacting steel frame contouring an existing opening is not a mere addition of stiffness and resistance for the structure.…”