Study On Structural Behavior Of T-structure Cable-stayed Bridge With Low Tower

The low-tower cable-stayed bridge has shown some advantages among the single-span 200m-300 m span bridges,especially the consolidation system of tower beam pier can not only meet the stiffness of train operation but also adapt to complex address conditions in railway construction,so it has a strong applicability.Taking the Changwan Lishui Bridge(172m 158 m low tower T-structure cable-stayed bridge)as the background project,the finite element calculation model of the bridge is established in this paper.Through the calculation and analysis,combined with the field survey data during the construction of the bridge,the structural stress characteristics of the bridge are studied.In this paper,the influence of different closing order,weight,design parameters of structural part on the force of the structure is discussed emphatically,and the influence of these factors on the force of the structure is discussed,The main contents of the study are as follows:1.The finite element calculation model of the whole construction process of the Changwan Lishui Bridge is established,and the stress variation of the key section of the bridge is analyzed and obtained.At the same time,the stress test elements are arranged in the key section of the bridge.The stress in the construction process of the relevant cross section is measured,the difference between the stress test results and the calculated results is compared,the stress variation law in the construction process of the key section of the bridge is analyzed,and the correctness of the finite element calculation model is verified at the same time.It lays a foundation for the performance analysis of subsequent structures.2.Relying on the single-tower asymmetric cable-stayed bridge consolidated by tower beam pier,it is well known that in order to control the deformation of bridge tower,reduce the deflection of main beam,increase the bridge stiffness and control the bending moment at the bottom of the tower,the general single-tower cable-stayed bridge usually adopts the asymmetrical arrangement scheme.But when the structure is unsymmetrical,it is difficult to carry out the symmetrical cantilever construction.In order to ensure the construction safety and control the bending moment of the main beam and the bridge tower,the small span often needs to be weighed,and there are also two options for the construction and closure schemes.One is that the number of segments of the two spans is the same,the length of the segments is asymmetric,the two spans are closed at the same time,and the other is that the length of the segments of the two spans is the same and the number of segments is different.The first is symmetrical cantilever construction,and the other is the closure of the later spans at a certain stage.Then continue the construction of the remaining phase of the main span,and finally close the main span.These two schemes have influence on the internal force of the structure,the counterweight needed to be increased in the construction,the construction cycle,and the construction safety.In this paper,the two construction schemes are calculated and analyzed in detail,and the results are combined with the calculation results.This paper discusses the influence of two construction schemes on the mechanical performance of the structure and the problems that should be paid attention to in their construction.The results of the study can be used as reference for the construction of similar projects.3.The cable-stayed bridge with low tower is a composite structure,a tower,a beam and a cable have an important influence on the force of the structure.There are different combinations of the three types of cable-stayed bridge,and the selection range of the three parameters is also large.In this paper,the influence of the parameters such as the height of the main beam,the arrangement of the stay cables and the area of the cable on the mechanical performance of the cable-stayed bridge with T-structure short tower consolidated by the tower beam pier is discussed through the comparison of the multi-group models and the change of some structural parameters based on the project.The results can be used as reference for the preliminary design of similar projects.