Prestressed Tendons Stress Increment Analysis Of Simply Supported Continuous T-shape Beam Bridge

In the process of bridge constructions in china, prestressed concrete simply supported continuous T beam bridge has many advantages in force and construction,for which it has been used a lot. Prestressed technology is adopted and plays a great role in improving the spanning capability and service performance of bridges. High strength materials are used,which can effectively reduce the quantity of steel and concrete in the components and the project cost. At the same time, it has advantages over improving the performance of concrete components. Prestressed tendons is the key force component in the prestressed structure.The stress distribution and the change of prestressed tendons can directly influence the bearing capacity and rigidity in the bridge structure.Therefore, taking the importance into consideration,the stress changes of prestressed tendons in main beams of this kind of bridges are studied.This paper relies on the three-span prestressed concrete simply supported continuous T beam bridge, Baobei River Bridge, getting the practical stress value of each construction stage of prestressed tendons. A testing bridge model is established by using the finite element software,Midas/Civil, and the prestressed tendons values in theory of measuring points in each construction stage are calculated. Through the compare between the measured data and the theoretical data,the correctness of the finite element model is verified.According to the calculation results of testing bridge finite element model, the prestressed tendons stress distribution each construction stage is analyzed, and the stress increments are discussed, resulting in obtaining the influence of different stages on the prestressed tendons stress increments. During the using phase, under different lanes load cases, prestressed tendons stress increments of each section in the axial direction are discussed,the prestressed tendons stress increments of different sections in the T beams with the same span are analyzed.It’s concluded that when under partial load,the tendons stress increments of the beam in partial load side are largest;when under middle load,the tendon stress increments of 3# beam are the largest.