Strong Ground Motion E ects on Seismic Response Reduction by TLCDs


Department of Civil Engineering,University of Tehran


Nowadays, various types of passive control systems are being used as an e ective solution
to reduce the seismic responses of structures. One type of these systems, the Tuned Liquid
Column Damper (TLCD), suppresses the input seismic energy by a combined action, including
the movement of liquid mass in the container, a restoring force on the liquid, due to gravity
loads, and the damping, due to liquid movement through the ori ces. In this paper, the possible
e ects of seismic excitation characteristics, such as frequency content and soil condition, on
the seismic performance of TLCDs, are investigated, using nonlinear time-history analyses.
For this purpose, a ten-story building was modeled as an elastic MDOF structure and used
for numerical analyses. For the time-history analyses, among the past strong ground motion
records of Iran, 16 records with di erent characteristics were selected. The results of this study
show that these characteristics play a substantial role in the performance of TLCDs and they
should be, accordingly, considered in the designing of TLCDs. In some cases, TLCD is able
to reduce structural displacement up to 50%, while, in most cases, the e ectiveness of TLCD
in reducing structural acceleration is not signi cant. However, it should be mentioned that, in
real applications, de-tuning may occur, due to the inelastic behavior of structures, which can
reduce e ectiveness. This study also shows that the displacement reduction capacity of TLCDs
is highly dependent on excitation characteristics, while the acceleration reduction capacity is not
that sensitive.