Abstract: In order to assess the working condition of the bridge structure system(BSS), based on the study results of the BSS components, a new method was proposed to assess the BSS reliability. The Markov process steady-state probabilities were used as the indexes for assessment of the BSS reliability, the relations between Markov process steady-state probilities and BSS components reliability indexes were established and a relational matrix R of the BSS reliability was deduced. For the real BSS, the system state transfer matrix may be established. Given the reliability index of every conponent of the BSS, the relational matrix R of the BSS reliability can be obtained. The steady-state probability of every state,i.e. the reliability assessment index, of the BSS can be derived by the Markov process steady-state probability calculation equation. An example showed that the proposed method is feasible and effective, providing a theoretical basis and practical method to BSS reliability assessment in the design and operation processes.

Key words: structural engineering, bridge system reliability, steady-state probabilities, markov process, reliability index