The Optimization Research On T Beam Externally Prestressed Reinforcement Technology

Small and medium span Bridges is an important part of the highway traffic network. Due to some reasons,such as the environment, design, construction and maintenance and so on, so many old bridges appear varying degree damage. Ensuring the safety of their performance has important economic and social significance. The method strengthens the bridges by external prestressing belongs to the category of an active reinforcement, which causes low degree of damage to the original structure, can largely improve the structure bearing capacity and control of the structure defection in the middle, cracks of beam bottom effectively. Thus it is widely used in engineering.In this paper, to a ordinary reinforced concrete simply supported T beam bridge which spans 20 meters, concrete grade, prestressed tendon area, prestressed tendon anchoring point in the horizontal and vertical are chosen as the variables, which are used in the analysis and checking computations of the carrying capacity and local stress. Results show that the external prestressing reinforcement can improve the bearing capacity of the original beam body effectively.With the increase of the prestressed tendon, the stiffness and bearing capacity is increased, and the bottom of the beam section the tensile stress transforms to compressive stress, and midspan deflection decrease significantly. At the same time,compared with the results of theoretical calculation and the results by using the finite element analysis,it is concluded that external prestressed strengthening method on the lower level of ordinary reinforced concrete T beam bridge reinforcement has good reinforcement effect.The conclusion in this article is that, in order to further promote the external prestressing method by which the bridges are strengthened and demonstrate the application of this method in the reinforcement of the low level of ordinary reinforced concrete T type girder bridge whose span are small and medium-sized,the result can be used as reference and basis.