RESEARCH ON MODAL PARAMETERS IDENTIFICATION OF BRIDGE STRUCTURE UNDER AMBIENT EXCITATION

The time domain united algorithms in modal parameter identification method for bridge under ambient excitation were studied,including the natural excitation technique and the eigensystem realization algorithm (NExT/ ERA).Numeric simulation of PC continuous beam bridge was carried out.During the simulation,practical influencial fac- tors such as acceleration measuring and outside white noise were taken into account.The validity of the method was veri- fied.It reveals that NExT/ERA is suitable for bridge's monitoring and diagnosis.