Research On The Sunlight Temperature Filed Effect Of Highspeed Railway Round-end Hollow High Pier

Under the natural meteorological factors such as solar radiation and air temperature,the temperature field inside the concrete hollow thin-walled pier is changing and redistributing constantly;the heterogeneity of its cross-section transverse temperature will cause the uneven distribution of the temperature strain inside the structure,thus causing the horizontal displacement of the pier top.However,the calculation of the initial boundary conditions of the temperature field,the analysis of the internal heat conduction of the concrete structure and the calculation of the thermal effect of the structure are the difficulties in the calculation of the displacement of the pier top of the concrete hollow thin-walled pier.In this paper,the temperature effect of concrete will be studied in the whole process,and the displacement of hollow thin-walled concrete pier top under natural environment will be effectively analyzed and calculated by theoretical analysis or finite element software respectively.According to the basic theories of general astronomy,solar physics and structural heat transfer,the heat transfer mechanism of concrete hollow pier in different geographical positions and orientations is carried out,and the relevant basic calculation formulas and required parameters in the calculation process of temperature effect are collected and sorted out.The boundary strip for the calculation of temperature field of concrete hollow pier in natural environment is systematically established Pieces.The corresponding calculation program of thermal analysis boundary conditions is compiled with MATLAB software.Combined with the temperature monitoring time history data of 68 m high pier of Jianxi super large bridge in Nanping City of Hefei Fuzhou high speed railway,according to the corresponding geographical and meteorological conditions,the thermal boundary conditions of concrete circular end hollow thin-walled pier are calculated,and then ABAQUS is applied to the transient calculation and analysis of structural temperature field.The calculation results are in good agreement with the monitoring data.It is shown that the calculation program of boundary conditions for structural thermal analysis established in this chapter is reasonable and effective.Under the condition of accurate calculation of temperature field,the calculation method of temperature effect based on structural mechanics is studied.Along the direction of wall thickness,the temperature field results calculated by ABAQUS are divided into sections to establish the corresponding regression equation of temperature calculation,and the temperature deformation effect of concrete hollow thin-walled piers with equal sections is calculated by section integral.The results show that the theoretical analysis method is in good agreement with the ABAQUS finite element software when the segment division is reasonable.According to the corresponding geographical and meteorological conditions,the boundary conditions of the temperature field analysis of the circular end concrete hollow thin-walled pier in the period of dichotomy and two to day are calculated.The time history distribution of the cross-section transverse temperature difference and the time history displacement of the pier top along the horizontal direction are analyzed.Under the same pier height,the cross-section transverse temperature difference directly affects the cross-section of the pier top Displacement value.Further analysis is made on the lateral linear change of 1#—5# pier caused by the displacement of pier top on the vernal equinox.The calculation shows that the maximum angle of beam end caused by the lateral displacement of pier top is 0.034 ‰ rad under the condition of non special climate in the natural environment,which is small and has no control effect on the safety of the line caused by the angle of beam end.