In this project the strong motion records taken from the 26 accelerographs located on and in the vicinity of the Vincent Thomas Bridge during the 1987 Whittier Earthquake will be studied. The study will: (i) define representative and appropriately correlated non-synchronous support motions, (ii) validate existing analytical modelling and seismic analysis, (iii) develop system identification techniques that deal with multiple-input multiple-output models (both linear and nonlinear), (iv) evaluate the bridge performance during the earthquake, (v) optimize the return on the instrumentation investment and improve the usefulness of the recorded-response data, (vi) propose a general program for strengthening or retrofitting of existing cable-supported bridges, (vii) obtain information on damping values as a function of the vibrational amplitudes, (viii) obtain information on the soil-structure interaction of this massive structure, (ix) develop elastic stoppers or other special devices to dampen the effects of seismic and wind forces. The study will fulfill an urgent need for comprehensive investigations of these unique and historical response records to insure the safety of suspension bridges which have been widely in use across the nation's seismic zones. The research results will be of extreme importance to strengthen existing cable-supported bridges (as well as to design new structure, and for up-grading and installing new monitoring instrumentation).
