Prestress force and moving load identification on prestressed concrete beam based on virtual distortion method

Prestress force (PF) is one of the most important parameters in prestressed concrete bridges as it determines the load carrying capacity of a bridge. Unexpected loss of PF may cause failure of a bridge which makes prestress force identification (PFI) critical to evaluate the bridge safety. No method at present could identify PF effectively. Vibration based methods have been used but require a determined exciting force which is inconvenient for in-service bridges. The best excitation for in-service bridges is normal traffic, but the load caused by vehicles is difficult to measure. Hence it prompts the need to investigate whether PF and moving load could be identified together..