Research On Mechanical Properties Of Prestressed Concrete Truss Beam Bridge

With the rapid development of economy, the bridge construction in our country has been rapid development, structural forms of bridge has gradually diversified, large-scale and light. Prestressed concrete truss beam bridge can give full play to the characteristics of high strength material, promote the structure light, has a very good ability of span, but also can effectively avoid the concrete cracking, at the same time, combined with the structure clear and the characteristics of simple structure, expansion joint less. In the present construction of bridges, it has been more and more improved and used.At present, the research on the mechanical performance of the prestressed concrete truss beam bridge is relatively less. This paper mainly studied the mechanical properties of the prestressed concrete truss beam bridge in the process of construction. Firstly, the construction method of the prestressed concrete truss girder bridge is studied. Secondly, the finite element analysis of prestressed concrete truss girder bridge is carried out, and the load test is carried out again. It provides reasonable reference of the same types of bridges. This paper mainly does the following work:(1)According to the construction method for plane frame section of prestressed concrete truss girder bridge, in order to improve the stability of the construction process, the construction technology of space frame section is put forward, and the construction drawing design is carried out. The construction control system of prestressed concrete truss beam bridge is built based on the method of the space frame section construction.(2) In view of the use of flat frame section, space frame section of the construction method of truss bridge, the finite element analysis model of truss girder bridge under different conditions is established. The stress of the control section of the construction process is analyzed, and the stress of the two structures is compared. The analysis results show that the stress values of tilt rod and the bottom chord are close. The stress of the vertical rod is different because of its layout, spread pull, the size of the cross section and so on. Due to the two kinds of structure system in wind bracing are different, the stress of the top chord varied greatly.Therefore, this paper considers that the construction method of the prestressed concrete truss girder bridge is reasonable, and the construction method is safe and reliable.(3)The prestressed concrete truss beam bridge under the action of static load control section strain and deflection is studied. It carries out to study strain and deflection of control section under the action of static load. The analysis results show that the bridge under test load is basically a flexible work state, have a certain security reserve capacity, satisfy the requirement of the design load standard bearing capacity.Under dynamic load, it tests the natural frequencies and impact coefficient of the bridge. In fact, the measured values are in good agreement with the calculated values.