Analysis Of Mass Concrete Temperature Field And Temperature Stress For Railway Bridge Pier On The Plateau

In the northwest of China, high speed railway appears constantly. These high speed railways adopt a number of massive piers and foundations at the time of construction of bridge piers and foundations. So the mass concrete appeared. As to mass concrete, the distribution of temperature field and thermal stress are extremely complex. In addition, in northwest plateau of our country, day and night temperature difference is very big, and the climate is very dry, relatively speaking, the climate is special. So if the construction of mass concrete is in such a special environment, the distribution of the temperature field and thermal stress distribution will be much more complex. Mass concrete will crack more easily, resulting in the normal use and durability of mass concrete structure be affected.On the basis of the construction, maintenance and the site temperature acquisition of some railway bridge pier platform, and the local meteorological data at that time, this paper applied MIDAS/FEA to establish the finite element model of 13 # pier, calculated and analyzed the temperature field of the concrete piers, simulated the temperature stress of the mass concrete piers, discussed the distribution of temperature field of mass concrete during the period of construction, explored the causes of the cracks. After analysis of these results, we can predict whether cracks appear or not in the pier concrete, and the location of these cracks. Then, compared the finite element calculation results with the actual measurement data, Improved the conventional temperature control measures, such as the choice of materials, operating methods and maintenance measures, discussed the countermeasures of mass concrete construction on the railway bridge pier, so as to provide technical guidance for later similar bridge pier construction. Specific content is as follows:(1)As to the 13 # pier which is constructed in the northwest plateau region in the autumn, applied MIDAS/FEA to establish the finite element model,calculated and analyzed the temperature field of the concrete piers, simulated the temperature stress of the mass concrete piers, discussed the distribution of temperature field of mass concrete during the period of construction, explored the causes of the cracks, outlined how does the temperature field and temperature stress change with the growing of age.(2)Sorted and analyzed the measured data, used EXCEL to draw the curve of the concrete temperature and time. Calculated the highest temperature of inside and surface temperatures of bridge pier with thermodynamic empirical formula.(3)Compared the calculation result of MIDAS/FEA software, the empirical formula calculation results and the measured values, to verify the correctness of the result of MIDAS/FEA analysis.(4)From the aspects of the influence factors of Concrete temperature and stress, studied how temperature difference between day and night and maintenance methods to affect the temperature field and stress field of concrete under the condition of fall in the northwest plateau.Proposed what should be paid attention to when construction and maintenance is in the northwest plateau region in the fall. And obtained a set of suitable technical measures to avoid crack for mass concrete of railway bridge piers in the fall of the northwest plateau area.