Seismic response control of base-isolated buildings using tuned mass damper

Earthquake response mitigation of base-isolated (BI) buildings with a tuned mass damper (TMD) is investigated. Two-dimensional reinforced concrete buildings having multiple degrees of freedom are numerically modelled. The placement of a TMD is varied on different floor levels and the building response under earthquake excitations is studied. The laminated rubber bearing (LRB), lead rubber bearing (N-Z), friction pendulum system and resilient-friction base isolator (R-FBI) are used as isolation systems for the buildings with 5, 10 and 15 floor levels. Newmark’s step-by-step method of integration is used for solving differential equations of motion of the coupled buildings. Installation of a TMD at different story of the BI buildings mitigates the acceleration at the top level and displacement at bearings. It is found that at increased time period of the isolators the effectiveness of the TMD is reduced. Further, for low-rise buildings, the placement of TMD has no significant role in reducing the response of the buildings. However, the efficiency of TMD placement is more noticeable for buildings with a larger number of stories.