1 A Study on Effect of Water Tanks Modeled As Tuned Mass Dampers on Dynamic Properties of Structures D. Rupesh Kumar, Ph.D. 1 ; M. Gopal Naik, Ph.D. 2 ; and Fahimeh Hoseinzadeh, M.E. 3 1 Assistant Professor, Department of Civil Engineering, University College of Engineering (A), Osmania University, Hyderabad 500007, India. E-mail: rk_dhondy@rediffmail.com 2 Professor, Department of Civil Engineering, University College of Engineering (A), Osmania University, Hyderabad 500007, India. E-mail: mgnaikc@gmail.com 3 M.E. Scholar, Department of Civil Engineering, University College of Engineering (A), Osmania University, Hyderabad 500007, India. E-mail: fahimehhz@gmail.com Abstract Here a suitable TMD system (water tank as a lumped mass without sloshing effect) is modeled on top/intermediate storey of building. The Response Spectrum method is considered as per IS 1893-Part1-2002. Seven RCC framed buildings are considered; rectangular buildings with vertical irregularity of 10, 14 and 20 storey with height to depth ratio (H/D) as 0.875, 1.23 and 1.6, respectively; and 14 storey L-shaped building with H/D as 1.23; rectangular buildings with vertical regularity of 10, 14 and 20 storey with H/D as 3.9, 5.44 and 8, respectively. The TMDs are modeled, with 3% total weight of each floor, using eight different cases. In total 63 building models are analyzed with/without TMDs by ETABS software and the results are presented. It is found that for extracting the maximum benefits, the buildings shall be modeled with three TMDs using 3-Gauss points at the intermediate storey as it reduces all the three parameters viz. time period, base shear and storey drift simultaneously to the maximum possible extent; and the reduction in the base shear is significant for buildings with smaller H/D as well as with higher H/D too. The TMD models are found to improve the performance of buildings under earthquake loads. Keywords: Tuned mass damper, Water tank, Earthquake load, Time period, Base shear, Storey drift, Height to depth ratio, Gauss points, ETABS software. INTRODUCTION Vibration control of environmentally induced motions in civil engineering structures has been a topic of intensive research over the last 30 years. A need for new and better means of designing new structures and retrofitting existing ones from the damaging effects of severe dynamic loadings has motivated civil engineer to embark on rather unfamiliar but innovative concepts of structural control. The use of lightweight, high strength materials, and advanced construction techniques have led to increasingly flexible and lightly damped structures, which is prone to cause human discomfort, structural damage and even failure in extreme dynamic loadings. The means to suppress undesirable levels of vibration have then become essential and integral aspect of structural system in tall buildings. AEI 2015 91 © ASCE AEI 2015 Downloaded from ascelibrary.org by New York University on 06/15/15. Copyright ASCE. For personal use only; all rights reserved.