Seismic Resistance Evaluation of Unreinforced Masonry Buildings

Abstract

The article presents seismic resistance evaluation study of unreinforced brick masonry buildings.The study was carried out as part of the Ph.D. research work of the first author. As part of the study, in addition to the standard laboratory tests, a dynamic field test was carried out on single-story, single-room unreinforced masonry structure. The model structure was tested in actual ground conditions against simulated earthquake vibrations produced through controlled explosions, especially designed for this purpose. Based on masonry properties accrued from lab and field tests, finite element models of the brickwork system were also studied. Finally, the software named, "Shear Damage Index (SDI)," developed as part of this study, was used to plot contours of shear demand (shear stress) to shear capacity (shear strength) ratio on the numerical model and hence to identify potential weak zones in the model for possible strengthening of those locations.

Seismic Vulnerability Assessment of Pakistan Unreinforced Masonry Buildings at a National Scale

“…Most modern buildings employ cement-based mortar, which consists primarily of one part cement and four to eight parts sand (Ali and Naeem 2007;Maqsood and Schwarz 2008a) and may contain locally available materials for improvement of mortar properties and reduction of cost. Mud or cement mortar is generally used to bond stones (Ali and Muhammad 2007), and in some cases no mortar is used at all, and wall cavities are filled with rubble to achieve an approximately level surface.…”

“…Ali and Naeem (2007) conducted a dynamic field test on a single-story single-room URM structure to understand the seismic vulnerability of URM buildings in Peshawar (KP). Ahmad et al (2010) adopted a non-linear displacement-based approach to conduct earthquake loss estimation of URM buildings in Mansehra (KP) and predicted significant economic losses (collapse of 12-33% of houses) and human losses (injuries and deaths of 7-17% of the population).…”

Frame-Elements Constitutive Law for Nonlinear Static and Dynamic Analyses of Masonry Buildings

“…The seismic response of masonry buildings either with reinforced concrete slab, ring/ bond beams, lintel beams, is mainly governed by the global mechanism primarily with shear response of the in-plane walls with limited energy dissipation capabilities and ductility (Javed et al 2006, Ali andNaeem 2007). The displacement-based method uses an equivalent nonlinear static SDOF system, called mechanical model in order to simulate analytically the response of an actual structure in terms of its displacement capacity, energy dissipation and secant vibration period.…”

Effect of natural fibrous plaster on lateral resistance of mortarless interlocking wall

“…Post-earthquake surveys have shown that unreinforced masonry structure most of the time suffer out of plane local collapse mechanisms (Sorrentino 2008). In order to get reliable analysis, estimation of damping energy is crucial (Ali 2007). Therefore, in this study, damping ratio of fibrous plastered and unplastered wall were compared to evaluate the contribution of fibre within plastering of masonry walls.…”