Safety Assessment For High Pier And Long Span Continuous Rigid-Frame Bridge In The Construction

Created the Xushuigou extra-long Bridge as engineering background, the dissertation analyzes the mechanical properties of high pier and long span continuous rigid-frame bridge and discusses the safety problem of this type of bridge when it is constructed on cast-in-place cantilever method. After structural and accident analysis for a general bridge and making use of the analytic hierarchy process (AHP) method, qualitative safety assessment of a general bridge on construction completed and the main risk factors are identified.Based on the qualitative safety assessment of a general bridge, the construction risks of the Xushuigou Bridge are assessed. The dissertation attains three potential significant risk factors—the loss of prestressing force in long reinforcement, the indeterminacy of concrete segment elastic modular ratio, the indeterminacy of concrete segment density. Subsequently, on the basis of related statistical analysis the dissertation presents the probabilistic model of the parameters mentioned above. Adopting Monte-Carlo random sampling analog method and large universal finite element program ANSYS, the failure probability of the Xushuigou Bridge is calculated. Afterwards, safety quantitative assessment completed. Some method of the structural risk control is also presented in the dissertation.