CALCULATION OF FUNDAMENTAL PERIOD OF INFILLED REINFORCED MOMENT RESISTING FRAMES

Ambient vibration measurements of many buildings have been recorded across the

world in the past to determine their dynamic properties, in particular, to ascertain the

properties of the fundamental modes of vibration. It is also recognized that the

experimental data from one region may not be used in another owing to the

differences in the construction methods and materials.

During an ambient vibration survey [Arlekar and Murty, 1997][1], a total of nineteen

buildings in Kanpur (India) seismic zone III are investigated to determine the

fundamental lateral transitional natural periods and the corresponding mode shapes of

vibration, as per the current seismic code for India. The investigated buildings are

reinforced concrete moment resisting frame (RC MRF) with un-reinforced masonry

bricks (URM) as infill walls.

Some infilled frame structures are analytically modeled using the standard analysis