Seismic damage and life cycle cost assessment of unanchored brick masonry veneers: Fid-Bau Portal

Seismic damage and life cycle cost assessment of unanchored brick masonry veneers

Reza Khalili, Mohammad / Ghahremani Baghmisheh, Amir / Estekanchi, Homayoon E.

Highlights • A simplified micro modeling approach is adopted to develop a numerical model of masonry veneer. • The crack pattern and capacity curve of the wall are validated using previous tests. • Seismic fragility models are generated for masonry veneers with and without opening. • A procedure based on the endurance time method is proposed to estimate the seismic fragility of veneers. • The life cycle cost of masonry façades is compared with that of curtain walls.

Abstract This paper develops the seismic damage models of brick masonry veneer attached to the masonry infill without metal ties and assesses the life cycle cost of veneers subjected to earthquake excitation. Even though anchoring veneers to the backup wall has been prescribed in recent building codes, most of the existing brick veneers in seismic prone areas around the world lack the anchoring details. Besides, the damage and consequence models of masonry façades have not been presented in the FEMA-P58 database restricting detailed performance evaluation of buildings with unanchored masonry veneers. This study develops detailed finite element models to simulate various failure modes of the masonry veneer units and joint interface. The modeling procedure is validated by comparing the capacity curve and the crack pattern of simulation with those of an experiment conducted on a masonry brick wall in the literature. Then, a new procedure based on the endurance time dynamic analysis is proposed to generate fragility models for veneers and the backup masonry infill with lower computational demand than conventional methods. It is found that existing of the opening decreases the median collapse capacity of the façade by 25%. To demonstrate application of the developed fragility models, the life cycle costs of three types of veneer, brick façade, and two types of curtain walls, for a ten-story steel building are estimated using the FEMA-P58 procedure. It is concluded that using masonry veneer induces considerable damage and loss at lower levels of earthquake intensity compared to the curtain wall. Despite the lower initial cost of masonry façade, the total loss associated with these façades is almost 70% greater than the total loss of curtain walls.