The Research Of Temperature Field And Effect Of PC Curved Box Girder Bridge Of City

With the rapid development of cities’ modernization, curved girder bridges have been widely used in practical engineering, for example:urban elevated, overpass. But "typical disease" problem was constantly found in the process of using is remarkable,The temperature effect is one reason causes typical disease of the curved girder. Bridge Design Specifications in city was developed based on Bridge Design Specifications in highway. In order to understand the bridge temperature filed in city and the contribution of temperature on the typical diseases, the article take a 2×5m concrete curved beam bridge model in city as research objects to test the temperature field for 2 years,then based on the observation data of temperature field by the simulation analysis.And discussed the city temperature effect under different structure parameters of bridge. The article is mainly focused on the following aspects:(1) Take a 2×5m concrete curved beam bridge model in city as research objects.Design the test programe of temperature and reaction force for the long time. Analysis the observation data by the spring, summer, autumn and winter, then concluded the most adverse temperature field of the year.(2) Analysis the heat exchange process of bridge in atmospheric, And concluded the box girder temperature field boundary thermal parameter calculation method. Combine ABAQUS program with the thermal parameters calculation method of the box bridge temperature field boundary to simulation analysis this bridge, the calculated values and measured values coincide well, that prove the establishment of temperature gradient mode is veracity..(3) Based on the observation data of temperature field, determined the mode of increment and reduction temperature gradient on this bridge.Then, comparison and analysis for the temperature gradient in the current specification. At last, take the numerical analysis of temperature effect on the bridge, compared with the measured reaction forces, the calculation reaction forces coincide well, that prove the finite element modal is feasible and reliable.(4) According to the environmental conditions of the measured area, studied the rule of stress, deformation and reaction force of the curved girder bridges under annual temperature and temperature gradient respectively. And analyse the relationship of temperature and typical disease of curved girder bridges. The analysis results show that:the temperature effect of annual temperature and temperature gradient have obvious difference; the curved girder bridges will produce longitudinal creep phenomenon under annual temperature, opposite the curved girder bridges will produce obvious radial offset or reverse under the temperature gradient.And in the fixed pier produced tensile stress, easy to produce cracks.(5) The analysis and comparison of temperature effect according to the measured temperature field of city and temperature field of Bridge Design Specifications in highway, and research temperature effect on radius of curvature and the bearing arrangement under temperature gradient of city. The results show that:the temperature effect under city temperature gradient is safer than the effect of specifications; Change the radius of curvature, the larger the radius of curvature, the smaller the radial displacement, at the same time, the smaller of reaction force difference. The curved girder bridges have more uniformly forced. By changing the bearing arrangement, the calculations show that:the small radius curved girder bridges usually take the torsional support and hinge support alternative arrangement. Adjust the spacing of the end torsional support, reduced the force difference of inside and outside under the increment and reduction temperature gradient, made the curved girder bridges have more uniformly forced of inside and outside.