Unreinforced Masonry Façade Assessment of a Historic Building for Excessive Displacements Due to a Nearby Subway Construction

Abstract

There have been numerous publications on unreinforced masonry construction in the literature; however, there is a lack of publications on the condition assessment of existing unreinforced masonry façades for disturbances due to nearby subway construction. To fill this gap, this paper presents a study in which a 5-story historical building with unreinforced masonry façade experiences inward and outward deformations perpendicular to the plane of wall due to nearby subway construction. The performance of the unreinforced masonry façade is examined under wind load combinations. For this, a finite-element (FE) model is built in ANSYS software to conduct a stress analysis of the brick façade. The results revealed that the tensile stresses exceeded the tensile stress limit at several locations; therefore, a structural remediation is required. A structural retrofit is proposed to tie the façade wall to the floor diaphragms with steel anchor rods at specific stories. Another FE model is built to represent the remedies proposed for stabilizing the façade wall. The results show that all stresses are within the limits, indicating that the structural solution for the remediation is appropriate. As a result of this study, the proposed remediation was implemented at the building, and the structure has been in good structural condition without any complaints, even after the subway construction was completed and the subway line was in operation.