Dynamic Reliability Analysis on Pounding of High-Pier Bridges Subjected to Stochastic Seismic Excitations

A dynamic reliability analysis based on the pseudo-excitation method in the frequency domain was proposed to investigate the pounding reliability of high-pier bridges subjected to seismic excitations with different ground motion intensity levels. A high-pier bridge was selected as the numerical example and the pounding reliability of the high-pier bridge was computed for each ground motion intensity level. The horizontal acceleration response spectrum was chosen as the seismic intensity measure and the response spectra for different intensity measures were converted into the corresponding power spectra. Next, the stochastic vibration equation was solved using the pseudo-excitation method to determine the mean and mean square deviation of the structural dynamic responses. The expected values and standard deviation of the structural peak responses were obtained using Davenport's theory. Finally, the pounding reliability between the adjacent beams of the high-pier bridge was determined using the first passage theory. The results indicate that pounding will not occur between the adjacent decks and the pounding reliability is 1.0 when the ground acceleration is less than 0.22g. In addition, there is an obvious decrease in the pounding reliability such that the structure collides under the strong ground motions when the ground acceleration is more than 0.22g.