Simulation Analysis Of Temperature Field In Mass Concrete Of Double-line Railway Bridge Pier In The Plateau Region

With the development of our comprehensive national strength and the progress of science and technology, Chinese railway is toward the development of high-speed and scientific direction. Bridge construction plays an important role in the construction of railway projects, so mass concrete structure also appears in bridge construction. However, mass concrete temperature field and temperature stress is extremely complex, especially in the large temperature difference between day and night,drought,and northwest plateau region, which will cause the mass concrete cracking, thus affecting the normal use and durability of the bridge.To a double-line railway bridge as engineering background, the paper makes simulation analysis of temperature field and temperature stress in mass concrete of double-line railway bridge pier. The paper mainly from the following four aspects carried out in-depth research and study:(1) The finite element theory about temperature field and temperature stress and associated with the main parameters selection are described. This provides a theoretical basis for the simulation analysis of the temperature field and temperature stress in mass concrete such as bridge pier and pile cap.(2) Due to drought and the large temperature difference between day and night in spring, this can easily make mass concrete cracking.So this paper makes deep study of the variation of the mass concrete temperature field and temperature stress, summarizes the mechanism of the thermal crack, and analyzes a variety of factors affecting the emergence and development of thermal crack through simulation analysis of temperature field and temperature stress in mass concrete of double-line railway bridge pier in the plateau region.(3) Through on-site engineering test and comparing the measured value and simulation value, the paper summarizes temperature gradient and the curve of difference in temperature in the spring, and verifies the feasibility and effectiveness of ANSYS on the temperature field and temperature stress simulation analysis of mass concrete such as the double-line railway bridge pier and the pile cap. For taking measures to control the development of mass concrete temperature crack, improving the design structure, slowing the cooling rate of the pier body and the pile cap, and adjusting the curing conditions are provided a technical support. This also play a guiding role in spring of mass concrete construction in the plateau region.(4) The paper focuses on the early mass concrete curing conditions such as different form stripping age, different curing conditions before and after the change in the form removal and other parameters. Through the pier body of the temperature stress simulation analysis, the paper summarizes the measures of more reasonable and economical concrete maintenance. The feasibility to a series of mass concrete construction control program from several aspects such as design measures,the pouring way of concrete.etc are also made deep exploration, so that this will easily carry out theoretical predictions and the monitoring of the internal temperature of mass concrete for later.