Study On The Side Effects Of Small Radius Curved Prestressed Concrete Girder Bridge

In recent years, with the development of elevated overpass construction in the urbanroad network, the small radius curved girder bridge is applied more and more widely. Thediseases caused by the side effects are increasingly apparent. So the research of themechanism of the side effects and the exploration of corresponding measures are full oftheoretical significance and practical engineering value to prevent these diseases.By means of analysing the bearing cavity and lateral creeping which triggered by theside reaction of small radius curved girder bridge, building spatial model with the help offinite element software: ABAQUS and MIDAS/Civil, and combining with the engineeringcases to analyse its variations of the counter force of the support structure and deformationdisplacement under the effect of dead load, prestress, vehicle load and temperature etc., thisdissertation focuses on discussing the factors of the two diseases: bearing slipping andlateral creeping which initiated by the side reaction. And combined with the results of theanalysis, from the angle of combat, this paper further explores how to set up rationalsupporting form and eccentricity to avoid these diseases. The main research conclusionsinclude the following:(1) The diseases triggered by the side reaction of curved girder bridge are notinfluenced by only one factor, but the result of coupling effect.On the phenomenon ofbearing cavity and lateral creeping that occurred in the cases, the effects of the gradienttemperature load, partial-load vehicles and prestress are significant. According to theanalysis of designing cases, setting resistant torsional bearing on the both ends, settinghinge bearing points on the pier top in the middle, and not presupposing the eccentricity arekey factors to initiate the side reaction of the bridges.(2) Through calculation and analysis, we suggest that the anti-torsional bearings in thesame link should be symmetrically arranged and the distance between them should keep inbalance. The calculated results showed that this rational support form which theanti-torsional bearings are symmetrically arranged in the same link and the distancebetween them are kept in balance can decrease the effect of side reaction.(3) Curvature radius is the negative factor to cause the side effects. Setting eccentricityof the small radius curved girder bridges can not only improve the distribution of torques,but also can reduce the torque value at both ends of the beam to make the bearing support reaction of the ends close, which can effectively avoid bearing cavity and lateral creeping.The torque which brought by the permanent effect of the curved girder bridge is greatlyinfluenced by the changes of intermediate eccentricity value. Through trial calculation, therational pre-eccentricity value increases when the curvature radius decreases, and we getpre-eccentricity approximate formula of the curvature radius.