Sensitivity analysis and monitoring of control parameters in cantilever casting construction of prestressed concrete continuous girder bridges.

To ensure smooth closure of prestressed concrete continuous girder bridges and compliance of structural geometric alignment/stress with design requirements, this study employs finite element modeling to analyze the impact of variations in key construction control parameters during cantilever construction on bridge alignment and stress states at both the final completed stage and during maximum cantilever conditions. The investigated parameters encompass concrete unit weight, elastic modulus, prestressing loss, concrete shrinkage and creep, and temperature. Coupling effects among critical parameters were analyzed, leading to the establishment of a construction monitoring system that incorporates coupled effects of key control parameters. Results indicate that temperature variations and prestressing loss exert significant influences on girder alignment and stress, whereas concrete elastic modulus and unit weight exhibit relatively minor effects. Consequently, parameters exerting substantial impacts on alignment and stress require priority in monitoring to guarantee successful closure during cantilever construction.