Effect of Building Height on Torsional Rotation of Base Isolated Structures

Abstract

The effect of height variation of a base isolated building on torsional response has been studied in the paper Also response of lead rubber and friction pendulum base isolator on torsional rotation has been compared. For the study, building rests on friction pendulum system (FPS) and lead rubber bearing (LRB) has been considered. The height of the building is varied successively and subjected to bi-directional seismic excitation. The torsional response of isolated structure is studied for each increment in the storey height for both LRB and FPS isolators and compared with fixed base structure. The result indicates that, base isolated structures reduces torsional rotation. It is also found that torsional rotation for buildings of ten to fifteen stores have significant reduction compared to other models considered in present study. Beyond this, the effectiveness reduces. It is also observed that FPS base isolator has effectively reduced torsional rotation when compared to LRB.