EFFECT OF EARTHQUAKE LOAD ON UNREINFORCED BLOCK MASONRY WALLS

Abstract

Unreinforced Masonry structures are susceptible to damage in earthquakes. It is therefore very important to
enhance the seismic capacity of block masonry buildings. Masonry is an effective alternative technique to improve
performance against and resistance to ground excitations. This research primarily focuses on the comparative study of
the unreinforced block masonry. One block masonry walls i.e. unreinforced were tested in order to compare their
strength, ductility and effective stiffness after the application of reverse cyclic loading. The values of displacement
ductility (µD), Response modification factor (R) and displacement amplification factor (Cd) were calculated. The three
performance levels namely Collapse Prevention (C.P), Life safety (L.S) and immediate occupancy (I.O) were calculated
with the help of ASCE standards to judge their performance level. It was observed that the Block Masonry Wall
performed superiorly in all the ASCE performance level conditions the Unreinforced Block Masonry wall. The
performance increased by 18% in I.O performance level, 2 7% in L.S level and by 25% in C.P level in case of
Unreinforced Block Masonry wall.