Field Test of Stress and Alignment of Curved Box Girder Bridges in Cantilever Construction

Field test and numerical analysis were conducted to investigate the variation laws of the stress and box girder bridges in cantilever construction processi¤The bending-torscoupling effect was discussedi¤Furthermore, temperature effecton the inner force and alignmentof curved boxgirder bridges were also discussed based on field monitoringi¤The results showthat (1) the differential stress between flange slabs, the differential deflection between two edges of top slab and the radial displacement increases with the curvature of boxgirder, the height of pier and the length of cantilever respectively; (2) thermal stress incurred byad, it changes with the variation of temperature gradient,constraint conditions and the length of cantilever; (3) thermal stress has lagging effect, the daily atmosphere temperature effect on elevation of boxgirder cannot be ignoredi¤The deflection of boxgirder increases with the atmo-sphere temperature gradient and the cantilever lengthi¤The influence of daily atmosphere temperature on the elevatof boxgirder also has lagging effecti¤The conclusions can be a reference forthe design and construction of prestressed