Analysis of cable-stayed bridges under multi-component random ground motion by response spectrum method

A response spectrum method is presented for the seismic analysis of cable-stayed bridges subjected to partially correlated stationary random ground motion. The method is based on the relationship between the power spectral density function and the response spectrum of the input ground motion, and the fundamentals of the random vibration theory. The analysis duly takes into account the partial correlation of ground motions between the supports, the quasistatic component of the response and the modal correlation between different modes of vibration. A cable-stayed bridge is analyzed under a set of important parametric variations in order to verify the responses obtained by the response spectrum method by comparing them with those obtained by the spectral analysis approach of random vibration theory.