Dynamic behavior of bridge pier with elastomeric bearings under earthquake effects for different soil layers and support conditions

Abstract

An isolated bridge pier having elastomeric bearings is modeled by finite element technique and dynamic responses under the effect of earthquake accelerations which are obtained by linear solution methods in time and frequency domain and the results are evaluated by probabilistic distributions. For this purpose, stationary accelerations characterized by Kanai-Tajimi power spectrum are simulated for different soil types and twenty nonstationary records in each soil group are obtained by modulating the amplitudes in harmony with 1992 Erzincan earthquake NS component. The pier responses and deck displacements are obtained in time domain for different support and soil conditions by using simulated horizontal and vertical accelerations. Furthermore, variances of the responses are obtained in frequency domain by assuming stationary stochastic behavior and by using power density and cross-power spectra of the applied simultaneous motions. The results are evaluated by those of the time domain solutions and peak responses and variations of peak response factors are determined. For dynamic peak responses, the response quantities corresponding to exceedance probabilities of 2%, 10% and 50% (median) are predicted depending upon soil types by use of Rayleigh distribution model.