Compatible Seismic Retrofitting of a Traditional Albanian Stone Tower Using Internal Textile-Reinforced Mortar Strengthening

Abstract

Most of the existing tradition of stone masonry towers is unique and irreplaceable in terms of Albanian traditional vernacular architecture. As most of them are situated in earthquake regions, the performance of unreinforced stone masonry is at risk. The brittleness of the material itself, the lack of internal connections between the masonry components and the general aging process lead stone masonry to deterioration. In this work, a numerical investigation of the seismic evaluation and effective retrofit of a two-storey traditional Albanian stone tower through the application of internal TRM overlay was conducted. The structural response of the building was studied in the existing condition and after the implementation of the Textile Reinforced Mortar (TRM) retrofit scheme by means of nonlinear static (pushover) analysis with the finite element based 3Muri software. The results illustrated show that the existing structure exhibits inadequate seismic performance, particularly in the X direction, where the NC, SD, and DL verifications are not satisfied. The safety factors are significantly less than unity across the Near Collapse (NC), Significant Damage (SD) and Damage Limitation (DL) limit states. With the internal TRM layers, the retrofitted model satisfies the required limit-state verifications and exhibits substantial improvements in base shear capacity, displacement capacity and seismic safety indices.This intervention maintains the original character of the building, and adheres to conservation principles. Therefore, this strategy could be used to seismically upgrade heritage masonry buildings in Albania or other similar Balkan countries.