The Deformation Analysis And Responses Of Highway Curved Bridge Under The Action Of Temperature Load

With the gradual increase of the national construction, civil engineering and transportation industry developed rapidly. More and more bridges are being built now because theory design knowledge is becoming more and more mature. Because of its outstanding advantages, the curved bridge obtained the engineers’ favor in these bridges. The highway curved bridge can not only solve the problems of straight bridge’ restrictions, but also give the bridge the curvaceous which is different from the straight line bridge. So in the traffic system of domestic and international city roads and highways, curved bridges play a very important role in the transportation of various states. Different from the straight bridge, the stress condition of the curved bridge is often very complicated. Because of its curvature, the bridge will produce coupled bending-torsional problems. So the disease and disease characteristics of the curved bridge is very different from the straight bridge. Even if it is not affected by the external force only due to its own weight will also make the structure itself produce torque.According to a large number of engineering cases it can be found that the change of temperature is a very important factor that may make the curved bridge exist potential safety.Associated with the existing literature, the development status and existing problems of curve bridge are studied in this paper. Then this paper measured the temperature field of single box double room box girder of LuLing Bridge with prearranged temperature measuring point. According to measurements, the temperature variation law of the horizontal and vertical of box girder section under sunlight action is analyzed. Then according to an actual example of curved bridge, the models is built to analysis the different temperature effect between the annual temperature change and sunshine temperature change, in different curve radius,between curved bridge and straight bridge, in different supporting formalism and eccentricity.The results of analysis can be summarized as follows.(1) The heating rate of the box girder roof was more rapidly than the lower parts of beam section under the action of solar radiation. The vertical temperature distribution of box girder presents the obvious nonlinear law.(2) The temperature stress of curved bridge under the action of solar radiation was far stronger than the stress produced by the annual temperature difference. The maximum temperature stress lied in the girder located at the secondary support. The horizontal and vertical displacement under the action of solar radiation was much less than the displacement produced by the annual temperature difference. But the possible security risks can not be ignored because of the rapid change.(3) With the decrease of the curvature radius, the horizontal displacement increased obviously and the maximum increment was in both ends of the curved bridge. So if thecurvature radius is too small, the curved bridge is on the rollover risk state under the action of solar radiation.(4) The lateral displacement of straight bridge is zero under the action of solar radiation.But the longitudinal displacement and temperature stress distribution are similar to the curved bridge in the same support forms.(5) The effect to reduce the temperature stress and displacement of a larger radius of the bridge was not obvious by setting all-torsion-bearing support. This kind of bridges can choose single hinged bearing while the ends of bridge setting all-torsion-bearing support.(6) It can reduce the lateral displacement of curved bridge without increasing the engineering quantity by presetting eccentricity. This method not only meets the requirements of the actual engineering, but also can improve the stress condition of the curve bridge.