Thermal Effects in Prestressed Concrete Cable-Stayed Bridge during Replacement of Closure Segment

Replacement of closure segment was first used to solve local failure in a prestressed concrete cable-stayed bridge. Its technical process mainly included removal of the disabled closure segment, reconstruction of a closure segment, and strengthening of the new closure segment. To check thermal effects during construction, the Yonghe Bridge was taken as an example and a finite element model was established. Then typical thermal load cases were considered. Results showed that removal of closure segment led to a modest reduction in the rigidity of main girder, so deflection at midspan, induced by thermal loads, increased notably. Regardless of removal of closure segment, the longitudinal displacement at the end of main girder and at the top of each pylon, caused by thermal loads, were also significant. Therefore, thermal effects should be reasonably estimated in theoretical analysis and variation of structural deformations with temperature should also be clearly identified in construction monitoring.