Research Of Temperature Effect Of Oblique Hollow Thin-walled High Pier

Abstract:With the stable development of the national economy, people’s demand of the transport line is growing. Structure department of highway changed the mode of thinking that the direction of routine should obey to the bridge, so that skew bridge is more and more applied. High bridge pier is more and more used in mountain areas and river valleys. As for the temperature effect caused by sunshine temperature difference, inside the high bridge pier there comes to be complicated temperature stress which makes the bad effect on the upper structure of bridge. But the research of sunshine temperature effect on the distribution of temperature field, the distribution of temperature stress, and the effect on upper structure caused by oblique crossing have not been conducted systematically. Based on No.5pier of Zhanghua Highway-Youshui Bridge, the sunshine temperature effect of oblique high pier was evaluated, specific content as follows:(1) Refer to lots of papers, numerical analysis of sunshine temperature field and the essential attribute of thermal analysis materials were conducted. Based on the classic thermoelastic theory and differential equation of heat conduction, by setting the boundary condition and initial condition, the finite element method of oblique pier was deduced. The essential attribute of thermal analysis materials include pyroconductivity, convective heat transfer coefficient, radiation coefficient, specific heat, enthalpy, heat generation rate, et.al. By research of thermal parameters, appropriate actual thermal parameters were selected for No.5pier of Youshui Bridge.(2) The determining plan of the distribution of temperature field was established. Since August2011, temperature sensors were inbuilt in the selected pier section based on the construction progress of No.5pier of Youshui Bridge. After the construction complete, data collection from the temperature sensors was conducted at time when is hottest and coldest, by the method of field test for3days, so that actual characteristics of temperature distribution were obtained.(3) Take the advantage of finite element software-Ansys for thermal analysis, the temperature field simulated analysis of Youshui Bridge No.5pier was conducted, and thermal analysis finite element model of oblique pier was established. The distribution of temperature field of Youshui Bridge No.5pier at the hottest and coldest time in summer and winter was obtained based on the data collected by field test and finite element analysis. On this basis, the single pier temperature effect and the change of upper structure transverse direction torque of Youshui Bridge No.5pier caused by upper structure restrain, sunshine temperature and the change of end reaction incurred by temperature effect were evaluated.(4) In the actual project, Youshui Bridge No.5pier and routine direction makes an oblique angle of25°. In the simulated analysis, by the adjust of model, the temperature effect at different angle was conducted. Compare the results of different oblique angle, the sunshine temperature effect based on the characteristic of the oblique angle was obtained, which can provide reference for the oblique angle arrangement of oblique bridge in the future.