ABSTRACT
ABSTRACT: Structural damage can be generally regarded as degeneration of working condition or performance degradation. For the designing a structure or its SHM system, it is significant to predict the structural damage under various mechanical and physical conditions as well as the mechanical behaviors of structure with damage. The process of structural damage analysis of PC girder bridge under prestress losing condition was studied in this paper. Demonstrated by a PC continuous girder bridge segment in Donghai Bridge, the losing evolution rules of longitudinal pretension in girder under operation condition was investigated, accordingly, its influence on the response of bridge in some key sections of the beam and the monitoring points were studied. The evolution laws of bridge static properties (Stiffness and Resistance) were discovered in order to give a deep understanding on structure static behaviors. The evolutions of the dynamic properties (Modal parameters) due to the losing of pretension were investigated too, which aims at detaching this variance from the one caused by local damage. The influence on statistical character of the acquisition data were explored, as a result, some statistical data processing routine can be designed under the guide of these apriority knowledge.
