Application Research Of T-rigid-frame Bridge Reinforced By External Prestressd Tendon

In our country, a great deal of middle and small span bridges were built in 1970s or 1980s.After several decades of services, the bridges show a few of deficiencies about their performances. With increasing traffic, bridges that are built in last century can't ensure structural safety. Therefore, strengthening the aging bridges is a very urgent task.At home and abroad, although there is a lot of experimental study about externally prestressing system, but the enforcement principles and design theories are still in the initial stage.In those cases, Summarizing of experiences in practical projects appear to be very important. In this paper, base on Guanzhou Panyu HongQiLi the second bridge practical project, profound research has been done on the reinforcement of T-rigid-frame Bridge with external prestressed tightwire.1,Calculation theories and methods about reinforcement of T-rigid-frame bridge with external prestressed tightwire are summarized in this paper. Analysis of prestressed loss in external prestressed tightwire, stress increment calculation and ultimate strength about the strengthened beam are also presented in this paper.2,Based on the practical project, Stress characteristic, design and construction scheme and the theory in the reinforcement of T-rigid-frame Bridge with external prestressed tightwire are studied in this paper. Their performances are analyzed service state and limit state.3,The paper analyzes practical engineering by finite element analysissoftware--bridge doctor and BRCAD and compare alteration on carrying capacityand alteration of principal tensile stress, believe reinforcement of T-rigid-frame Bridge with externally prestressed tightwire enhance safety storage of bridge. The reinforcement of T-rigid-frame Bridge with externally prestressed tightwire is a feasible and effective method.4,3-D finite element model about bridge dynamic characteristic has been established. In the processing of vibration, based on dynamic characteristic determined by structural mass and rigid, component mass and rigid have been calculated, its dynamic characteristic can be obtained. 5,The zone of bracket is a weak part in the bridge structure. The bracket 3-D finite element model has established by ANSYS. After analyzing of bracket zone, tension stress can be obtained and its tension stress concentrated zone can be found out. The paper provides credible gist by evaluate reinforced effect of bracket zone.The result in this paper which has high practicality value to the practical project is a good reference to T-rigid-frame bridge strenghing designment and construction.