In order to eliminate the adverse effect of shear key disease on prefabricated voided slab bridges,scheme for an transverse prestressed voided slab bridge with partial-depth shear key is proposed.The full scale model experiment and nonlinear finite element analysis of a 13 m-span voided slab bridge are carried out to study the mechanical performance of the bridge under load.The test results show that the normal bond strength of the partial-depth shear key junction surface is 40％of the tensile strength of the weak side concrete.The tangential bond strength of the junction surface is 1.1％of the compressive strength of the concrete axis on the weak side.The shear key and the junction surface between old and new concrete remain well during the test,and the failure of the voided slab comes before the shear key.The failure mode of the transverse prestressed prefabricated voided slab bridge with partial-depth shear key is the voided slab failure,and the shear keys are no longer the weak part of the voided slab bridge.The finite element calculation results show that the transverse prestressed greatly reduces the normal tensile stress of the shear key junction surface.Shear failure rather than flexural failure occurs in partial-depth shear key junction surface of voided slab bridges.The results of parameter analysis show that when applying transverse prestressed,the value of the prestressed should not be less than 45％of the standard strength of prestressed reinforcement.
关键词
装配式空心板桥/浅铰缝/横向预应力/受力性能/足尺模型试验/有限元分析
Key words
prefabricated voided slab bridge/partial-depth shear key/transverse prestressed/mechanical performance/full-scale model experiment/finite element analysis
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