09-10-2014, 04:37 PM
In this project work an attempt has been made to study the failure pattern of a
box-type unreinforced masonry building under the action of base motion. Prior
to the testing, free vibration study was carried out to obtain the fundamental
mode shape, frequency and damping. For the purpose of base motion
simulation, a shock table was fabricated such that the cross walls (longer walls)
of the box-type structure were subjected to out-of-plane motion. Also, due to the
limitation of input energy, a scaling ratio of 1/6 was adopted. To reproduce the
typical disposition of bricks, which is an important feature of a typical masonry
building, scaled bricks were made. The scaled bricks were made of stabilized
mud. The scaling facilitated drastic reduction m the mass on the shock table.
Two scaled model buildings were tested; one made of cement mortar and the
other made of lime mortar. The accelerations at the base of the model, and at
two points on the building were measured, The strength and elastic properties of
the masonry used were measured. This has been used in the linear finite element
dynamic analysis. The experimental results were compared with FEA.
It has been concluded that shock table study is very useful in understanding the
dynamic behavior of simple masonry structures. Further work needs to be
carried out to achieve better scaling requirements for dynamic testing.