The Analysis And Prevention Of Cracks For Beam-T Simple-continuous Girder Bridge

The prestressed concrete simple-continuous T-beam bridge has been widely used in the construction of modern bridges because of its many advantages.However,this kind of bridge occurs some typical diseases in construction and services,such as the cracks at the deck and the bottom of mid-span and these cracks will directly affect the security and durability of the bridge.Based on extensive research,this paper makes a statistical analysis for the simple-continuous T-beam of one expressway in Yunnan.The location of the cracks is classified and the general law of cracks is confirmed.Then,according to an example project,the finite element model is established by MIDAS/Civil software.The mechanical behaviors of the simple-continuous T-beam bridge are analyzed in prefabrication stage,installation stage and service stage to get some countermeasures of cracks.In prefabrication stage,this paper studies the simplified calculation method and the distribution law of the internal force and stress of the beam under the constraint by the base,and explores the influence of early shrinkage and creep of concrete on internal force and deformation of structure,and studies the distribution of internal force and deformation of T-beam structure with different loading ages..In installation stage,this paper explores the key processes of the structural system conversion process and the impact of construction defects on structural performance.The influence of the difference of pouring sequence of the continuous section on the pier the diaphragm on the structural force and deformation are further studied.In service stage,this paper studies the effect of different prestress degree on the overall mechanical behavior of continuous beam.The influence of the pipe friction on the mechanical performance of continuous beam bridge is considered.The influence of different transverse contact on the mechanical properties of simple-continuous T-beam bridge is also studied.Based on study above,this paper proposes some suggestions and countermeasures for the cracks of the simple-continuous T-beam bridge in the construction.