Btrm Seismic Strengthening Arch-type Opening Rc Frame Steel Frame Urm Wall

External authors:

• Felipe Orduz ( Pontificia Universidad Catolica de Chile )
• Erika Ortega-Guaman ( Pontificia Universidad Catolica de Chile )
• Luis Perez-Pinedo ( Pontificia Universidad Catolica de Chile )

Abstract:

This paper presents an experimental investigation of three strengthening strategies aimed at improving the inplane seismic response of unreinforced masonry (URM) walls with arch-type openings. To this end, four identical full-scale walls were constructed and tested under cyclic in-plane lateral loading: one unstrengthened control specimen and three strengthened walls using (i) basalt textile-reinforced mortar overlays, (ii) steel frames combined with anchored steel bars, and (iii) a reinforced concrete frame partially embedded in the wall thickness. The seismic performance of the tested walls was evaluated based on lateral load-displacement response, damage evolution, and key seismic parameters. A brief evaluation of the implementation cost and practical applicability of the strengthening strategies was also conducted. According to the results, the strengthened walls exhibited increases in maximum lateral load of 25-73% and in ultimate displacement of 56-81%. Although all walls exhibited a predominantly flexure-controlled response, the strengthened walls developed wider hysteretic loops and dissipated energy increases ranging from 44% to 122%, suggesting a greater participation of shear-related mechanisms in the overall response. Variations in ductility relative to the control specimen were also observed among the strengthened walls. These results provide novel experimental evidence on three strengthening techniques for URM walls with arch-type openings, along with their implementation costs and practical applicability, to support informed decision-making in seismic intervention projects.