Research On The Service Behavior And Flexural Capacity For Highway Prestressed Concrete T Beam

With the continuous development of Chinese bridge construction, more and more prestressed concrete T-beams have been used into the highway bridge. But the prestressed concrete structure’s actual stress working behaviors are quite complex, especially after cracking, the changing of flexural stiffness and the influence of carrying capacity, these are the problems for engineers concern. Now, in spite of that we have the detailed design method of prestressed concrete T-beam, but still have lots of factors on site affect the beam system, and whether it can meet the requirements rarely have experimental verifications. Due to the loading conditions and costs, the experiment about full scale beam is still relatively seldom. So it has an important engineering significance for the experimental study of the site prefabricated T-beam.In this paper, I have selected the site prefabricated T-beam of 30 m for researching. Through observing the whole process of the static load test and building the simulation analysis of ANSYS software, research its working coditions in normal use stage and its characteristics in destrucion stage.In this paper the main resarch content as below:(1)After summarizing study of the common short-term stiffness methods of bridges, I know that there are 6 kinds of main methods such as linear bilinear method, curvature integral method, effective moment method, partially prestressed concrete design suggestion method, stiffness analysis method and highway bridge design standard method. Because the linear bilinear method and the highway bridge design standard method are commonly used in engineering, I select both of them to calculate the stiffness values, and compare with the experimental calculation stiffness, getting a conclusion that the calculation values and the estimated values of the test have a better consistency.(2)Doing static load test. Before the test, I will calculate its cracking load and ultimate load according to the design requirements, in order to set the test’s load cycle. During the test, observe the whole failure process of the T-beam, and record relevant dates about the respective stages such as deformation, strain, crack and so on. The results showed that the working states of the T-beam can be divided into three stages, the performance of working is basically consistent with the existing norm.(3)Application ANSYS to simulate the failure process of the test beam. The first job is to define the T-beam’s parameters, then establish its 3D model. After that, simulating the whole experiment process and getting its development laws through the deformation, stress, cracks and so on. Last but not least, comparing with the experimental results, have verified the feasibility of establishing model and the correctness of defining parameters.(4)Through comparing with the experiment’s stiffness variation law, ultimate load and so on, determine that the experimental beam has a great working performance and adequate safety reserve, meeting the design requirements.