Optimization Design Study Of The Prestressed Concrete Continuous Box-Girder Bridge

The carrying capacity of box girder bridges are closely correlated to the present design idea and procedure according to the recent study of box girder bridges such as continuous bridges and continuous rigid frame bridges. However, the relevant standard for concrete box section components both from domestic and abroad is primarily based on that for T shaped or I shaped section components therefore employing this method could not precisely analysis the action of mechanics on the object structure.Based on a certain load test for a bridge, by simulating and calculating with the variation of some design parameters, this article proposes some optimization recommendations. The main contents and conclusions as follows:1. This article summarizes the selection of the detail parameters for box girder bridges in design and the load test procedure, such as the selection of the section profile and the selection of the width of the web and bottom plate.2. The main procedure of load test is briefly presented and the feasibility of simulation is proved by simulating the load test and comparing the results between simulation and actual load test.3. By the finite element method and variation of part of the design parameters according to the structure features of the bridge, including changing the width of the bottom plate, the arrangement of the prestressed tendon and both of the above, it draws the conclusions as follows: the mid-span deflection is obviously effected by the width of the bottom plate; the influence of the carrying capacity by rearranging the prestressed tendon is not distinct; the deflection of the structure shows tremendous decrease at the circumstance of widening the bottom plate and placing the prestressed tendon both in web and bottom plate, which can brings the prestressed tendon into its better play.