Structure Analysis And Design Research Of Prestressed Concrete Chord-Stayed Truss Bridge

Prestressed concrete chord-stayed truss bridge is a new bridge style with great development in these twenty years.It has been changed on the base of PC continuous beam-type bridge with the similar structural feature with cable-stayed bridge and truss bridge.The main advantages of this new bridge are lighter self-weight,bigger rigidity, more clear stressed characteristic and higher material utilization.The main reason that this bridge hasn't been built wildspread is lack of profound structural research and majorized design method.This paper connected with the project Kaziwan Bridge in the Three Gorges Reservoir Zigui County is on the base of the subject"the Research of Committed Technic about Prestressed Concrete Chord-Stayed Truss Bridge".The purpose of this paper is to research the static and dynamic characteristic under different loads,define the value of the design parameter and induce the structural characteristic and majorized design method through creating and analysing the spacy finite element model.According to the analysis and research,the main conclusion of this paper is gained below:generally,upper chords and some web chords bear tensile stress,other web chords and lower chords bear compressing stress;the characteristic of the upper chords and lower chords near the sopports of abutment;the longest web chords on the top of the main pier bear compressing stress in fact; the value of stress is connected with their position along the longitudinal direction:more close to the main pier,more high stress the chords wil have;the stress of all chords is mostly generated by axial force but lightly by moment;the stress of the chords and the vertical displacement of the nodes are mostly influenced by self-weight and lightly by other loads,however the horizontal displacement are mostly influenced by thermoload and lightly by other loads;generally,design of the structure is most reasonable while the value of the angular between upper chord and lower chord is 15°.The conclusion of this paper can be used in the research of structural characteristic and majorized design of prestressed concrete chord-stayed truss bridge later.