Study On Lateral Displacement Of Highway Ramp Bridge

Nowadays the specification fails to keep pace with requirements of infrastructure’s development, or there is no related standard about the ramp bridge. Meanwhile, the number and variety of ramp bridge are increasing. What’s worse, lateral displacement is one of the main diseases of ramp bridge. Therefore, the study of lateral displacement has a very important significance for the future design and reinforcement.In this paper, the study of ramp bridge is based on an interoperable ramp bridge in Guangdong. Using large-scale finite element software scaled the ADINA, the study analyzes the space simulation of bridge, steel bar, steel strand and the reinforcement, and compares the before and after reinforcement. Besides, it analyzes the collapse of ramp bridge in Guangdong He Yuan under different bearing systems.The paper studies the displacement of the ramp bridge under different factors such as constant load, prestressing force, temperature, temperature gradient, live load, centrifugal force and braking force, especially under the most unfavorable combination factors. The ramp bridge has two kinds of lateral displacements, they are the vertical and horizontal lateral displacement. The vertical displacements is far greater than horizontal displacement. The lateral displacements of ramp bridge is the result of the composite of the vertical and horizontal displacements. Form the influencing factors of ramp bridge’s displacement, the study finds temperature and prestressing force are the main factors, especially hypothermy. Ramp bridge is curved, different from horizontal curved bridge, the component of gravity seriously hinders the restoration of ramp bridge. Under the influence of external factors, the top of ramp bridge has a tendency to climb to the curved side, but the bottom of beam end moves to the inside. The accident of ramp ridge in Guangdong He Yuan has proved this theory.Due to unclear early understanding of ramp bridge, and the unreasonable usages of a large number of single column piers and supporting systems, ramp bridges have advantages to displace. For the collapse of ramp bridge in He Yuan, overload is the direct cause, the displacement is the indirect cause, the ultimate reason is the unreasonable supporting system. Setting the vertical unidirectional bearings can limit lateral displacement; setting the consolidation in the piers can limit longitudinal displacement; setting up double bearings in the cross eccentric will balance supporting reaction forces inside and outside the beam end, which will improve the torsional stiffness of the beam body.