Optimal design parameters of brigde bearings for seismic protection

ABSTRACT

In this paper, optimization of bearings and dampers to improve seismic performance of bridgefs is studied. At the first half of the paper, general optimization procedure for seismic response reduction is constructed. The seismic excitation is modeled by stationry gaussian wthite noise for the convenience of the analysis, and the expected peak response is expressed in terms of the response spectra by applying simple approximation on peak factors. Then, optimal design values are derived by minimizing mean square responses of interest. Following the construction of the general method, optimal design of deck connections and bearings are demonstrated using simple linear two-degree-of-freedom structural models. Analytical expressions for optimal design values are also developed for these devices. The validity of the proposed optimization procedure and design values are studies using the observed ground motions of 1941 El Centro earthquake, and 1995 Kobe aerthquake. (AU)