Analysis Of The High-pier Long-span Continual Rigid Frame Bridge Under The Temperature Load

The bridge being put in the external environment which receive the outside influence of the temperature effect, which is difficult to accurate calculation but is simplified consideration. In the reality many bridge accidents were confirmed that is temperature effect is not well advised. At present the various countries' design codes about the concrete box beam temperature load is inconsisten. This article depends on the Hubei province HuRongXi express highway temperature field tests of Long Tang River bridge's pier and box-beam,which have a good research of the high-pier long-span continual rigid frame bridge arouses temperature gradient and temperature stresses by the solar radiation.Some work and achievements in the research as follow:1.the temperature distribution in concrete box girder section caused by the solar radiation is nonlinear, the curse of vertical difference in temperature obtained in the way of curse fit can be expressed as exponential function as Ty =17 e^-5.7y and the linear difference in temperature 2℃at the range of 20cm to the bottom slab. The bridge pier nonlinear temperature along the bridge can be expressed as Tx =10.5 e^-6.03x,and the pier nonlinear temperature horizontal the bridge can be expressed as Ty =7.4 e^-5.50y.2. The temperature stress in box girder is calculated in two-dimension model and three-dimension model respectively. The tensile stress resulting from nonlinear difference in temperature in web is strong, so the designer should pay attention to the response of temperature effect in order to protect the concrete from cracking in design. Pier's stress by the solar radiation is small but the displacement effect of the pier by the solar radiation is bigger to the block top , the maximum amounts to 2.4 cm.3. This article has analyzed the Long Tang River bridge's midspan deflection increasing under the cyclicity temperature load by the periodic load fatigue theory and the elasticity coefficient discount methods. The temperature load influence of the pre-camber in the continual rigid frame bridge construction process.