Study On Mechanical Properties Of Prestressed Concrete Trough Girder With Transverse Prestress System

With the advantages of low building height and high utilization rate of section space,the trough girder bridge has been widely applied in urban rail transit.Traditional trough gieder usually uses a three-way prestressed system when the span is large.Because the prestressed pipelines are interlaced to affect the vibrating construction of the concrete,cracks are likely to occur at the corner of the web and track bed.In this paper,the full-scale load test and the finite element software ABAQUS are used to study the mechanical properties of a 35-meter prestressed concrete trough girder with transverse prestress system,which provides a reference for the design,construction and engineering application of this kind of trough girder.Firstly,a full-scale load test of a 35-meter prestressed concrete trough girder with transverse prestress system is carried out to obtain the deformation characteristics,cross-sectional stress distribution,cracking load and crack development of the girder under the test loading condition.The working performance under the design load and the crack resistance under 1.2 times of the design load is evaluated.Secondly,the finite element software ABAQUS is used to establish a solid finite element model of the prestressed concrete trough girder with transverse prestress system.The stress and displacement of the girder under different load levels calculated by the finite element method are compared with the test results to verify the consistency of the two.Then,ABAQUS is used to analyze the mechanical properties of the girder under self weight and prestress,the design load and the crack resistance under 1.2 times of the design load.Thirdly,the finite element software ABAQUS is used to study the cracking load,crack distribution and crack width of the girder.The research results are compared with the test results to verify the accuracy of the concrete damage plastic model established in this paper in simulating concrete cracks.Finally,the finite element model of the trough girder without transverse prestress is established,and its mechanical properties are compared with that of the trough girder with transverse prestress.Through comparison,the necessity of arranging transverse prestressed reinforcement is explained.In addition,the reasonable reinforcement method of the transverse prestress is studied.