Analysis and Design of u-shaped Prestressed Precast Girder

Abstract

In India generally the bridges are constructed with cast in situ construction technique. In the bridges prestressing technique is used frequently due to cost e ectiveness. The prestressed construction is of two type post-tension and pre-tension. The concept of pretension prestressed construction system is used in construction of precast element. Di erent types of the bridge superstructure are constructed in India such as Slab, T-shape, I-shape, Box shape, Arch type etc. Depending upon the requirement of the bridge selection of superstructure has been done. In present scenario, aesthetic of the bridge structure is the important aspect in design of bridge. Generally, in India railway bridges are constructed with steel section. During the Delhi Metro project and Mumbai Metro project the concept of precast prestressed bridge superstructure with U-shaped has been implemented. The precast construction reduces time duration of project which result in saving in the cost. The precast girder has good aesthetic as compare to cast-insitu girder due to quality management. Due to the U shape of girder it will obstruct view of machines part of rail which result in good view of rail. The prestressed precast U-shaped girder may be give new dimension to bridge superstructure. The U-shaped girder has better scope as it can replace current trend of design of bridge with I,T or Box shaped girder. In present study, the analysis and design of U-shaped girder for railway loading is done with speci cation of Concrete bridge rule under Indian Railway Standards. The parametric study of the superstructure for span with various depth for broad gauge and meter gauge loading is done and economical span to depth ratio is found out. The design sub structure is carried out which include design of bearing, piercap, pier, pilecap, pile. The drawing of super structure and sub structure is prepared.