ANALYSING AND MODELLING RECORDED EARTHQUAKE INDUCED STRUCTURAL RESPONSE

Abstract

Earthquake induced acceleration data has been systematically collected in two reinforced cast-in-place concrete buildings over periods of 14 and 5 years respectively and the database from the two buildings presently contains 870 records from 107 events ranging from magnitude 2 to 6 with acceleration amplitudes of up to 34 % g. This data is used to examine structural behaviour and system parameters and their dependence on excitation conditions. The system identification based on the sampled data serves both as a baseline for damage identification as well as calibration for further structural modelling of the buildings. Visible damage is slight, but the system parameters reflect structural changes. There are clear indications that the system parameters are amplitude dependent, even for relatively small response amplitudes. Inelastic dynamic analyses were also carried out on one of the structures to investigate the reliability of the analytical models and to estimate the capacity of the building to sustain future earthquake events. The results show that the model does represent the structure and although it came through the recent earthquakes with no damage the structure has limited capacity to withstand any event that would be larger than those experienced to date.