Analysis On The Practical Design Method Of Irregular Shaped Prestressed Concrete Bridge

With the rapid development of transportation enterprise,the existing urban roads and bridges have couldn't satisfy people's needs already.Overpass and plane cross bridge form have been widely used,thus a lot of irregular plane bridge structure gradually generates.And this irregular bridge form has generally referred to as the special-shaped beams.The structure of special-shaped beams has complex force,while the calculation theory and design method of them have a little backward than straight beam.So,the study of design method of special-shaped beams has significance.The research status at home and abroad of special-shaped beams structure has been expounded first,and then two typical kinds of entity model of special-shaped bridges are built by the finite element software.And the following results have been studied.a.The static response of two typical kinds of special-shaped bridges have been analyzed under the dead weight,prestress,vehicle load and the combined loads.And the spatial effect of special-shaped box girder are discussed,so the mechanical characteristics of special-shaped bridges are definite.Considering these,some advices about the design method of special-shaped bridges are given.And the mechanical characteristics of two structure have been compared and analyzed.b.The stressing influence on special-shaped bridges caused by the designing parameters,radius of ramp,section height and thickness of dark beam,is analyzed.And The Taguchi Experimental method is used to analyze the combined effect resulted by the above three parameters.The stress effect on the main girder when three parameters changes together is definite,and the safest scheme is get.c.The finite element method is used to get the eccentric coefficient of two kinds of structure control section influenced by different parameters,and the relationship between the eccentric coefficient and the designing parameters is concluded,which is to guide the structure design.Last,comparing the suggested method with empirical method,the eccentric compression method and the corrected eccentric pressure method,the practicability of this method is illustrated.d.Two entitative engineering belong to two kinds of structure,branching structures and integrated structures are chosen to verify the result and law concluded by the suggested method.