Research On Crack Prevention Of Prestressed Concrete Continuous Curve Box Girder Bridge

Prestressed concrete continuous curve box girder bridge is very common modern urban traffic and highway bridge because of its beautiful and smooth fluent line shape. It can well satisfy road horizontal alignment and has become the main type of overpass ramp bridge. But continuous curve box girder bridge belongs to space structural system, its salient features is bending-torsional coupling effect. Influenced by bending, twisted, the shear-lag effect and torsional deformation, box section's mechanical characteristics are very complex. Prestressed cable of curve beam is double curvature cable in geometry, so its equivalent force and prestressed friction loss is more complex than straight bridges.Using the static and dynamic load test and finite element models to analyze the stress and deformation characteristics in different conditions of prestressed concrete continuous curve box girder bridge, it provides a powerful proof for prestressed concrete continuous curve box girder bridge crack prevention.This paper summarizes the design theory and calculation method of prestressed concrete continuous curve box girder bridge. With prestressed concrete continuous curve box girder bridge as the background, use Midas which is a finite element analysis software to analysis structure. Set five different prestressed adjustment scheme to analysis stress changes of curve bridge and compare with the original program. Through the analysis, find out that if the inside and outside ribs the box girders are gave asymmetric pre-stress, it can effectively improve stess performance, reduce the bending-torsional coupling effect and prevent the cracks occurring. Analysising influence to curved girder Bridges by the different curvature radius, temperature effect and crossbeam, the deformation and stress rule of prestressed concrete continuous curve box girder bridge will be summarised and the factors influencing curve box girder bridge crack will be found.