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Identification of dynamic properties of low and medium-rise buildings in Bangkok by an ambient vibration method | |
Author | Charkorn Petcharoen |
Call Number | AIT Thesis no.ST-02-14 |
Subject(s) | Buildings, Reinforced concrete Thailand Bangkok |
Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering. |
Publisher | Asian Institute of Technology |
Abstract | Dynamic properties of thirteen low and medium-rise reinforced concrete buildings in Bangkok, varying in height between 20 and 80 meters, have been identified by ambient vibration measurements and the frequency domain technique, developed by Trifunac. Some modifications of schemes of measurements and the spectral ratio method are used to identify 3-D vibration mode shapes at top floor level. Controlled human excitation, which generates an inertia force to a building from the movement of human bodies, was applied to amplify the low amplitude responses of particular modes of these buildings in order to obtain accurate dynamic properties: natural frequencies, vibration mode shapes, and critical damping ratios. The responses of fundamental modes are successfully enhanced by this application with a few people. The dynamic properties of fundamental modes of these buildings are extensively studied. Regression analysis based on present fundamental period data is used to estimate empirical formulas for fundamental periods of reinforced concrete buildings in Bangkok, as proposed in this study. The critical damping ratios are identified by the autocorrelations of ambient responses and free vibration responses obtained from the controlled human excitation. It is observed that damping ratios obtained from higher amplitude responses, free vibration responses, are higher than those in low amplitude responses, ambient vibration responses. The 3-D vibration mode shapes show coupling motion of translational and torsional motions and their vertical profiles are used to calculate effective modal mass ratios, ones of modal parameters, in order to characterize the deformation behaviors of the buildings, which may affect the way strncture responds to dynamic excitations. |
Year | 2002 |
Type | Thesis |
School | School of Engineering and Technology (SET) |
Department | Department of Civil and Infrastucture Engineering (DCIE) |
Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
Chairperson(s) | Pennung Warnitchai |
Examination Committee(s) | Kim, Kidu;Barry, William J. |
Scholarship Donor(s) | Government of Thailand |
Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2002 |