The Theory Of Environmental Thermal Stresses On Basement External Wall And Floor And FEM Analysis Research

At present, the throughout the country have emerged many high-rise buildings, building by all the year round temperature effect, the temperature cracks are very common. Engineering important job was to heat preservation of the building and temperature controlling role. Due to the basement structure is different from the mass concrete structure, nor the exact equivalent of industrial and civil architecture rods system, is between two composes of super statically determinate structure, due to the basement structure its binding larger, and underground building waterproof requirement, once wallboard cracking caused by leakage its very dangerous.Taking shenyang climate characteristics as the research background, theoretical analyses and studies the basement wall floor in the external environment temperature under the action of structure effect. By the environment temperature stress analysis as theoretical basis, using three-dimensional finite element model of linear elastic analysis method to establish the basement structure model, wallboard and soil using elastic and constraint. This paper studies the basement wallboard in concrete strength has achieved 100%, elastic modulus thermodynamic parameters such as with time changes, i.e. not consider early concrete temperature stress but study later temperature stress (this paper says environmental temperature stress). And that the basement wallboard maturity. At this time the concrete surface by environmental temperature of daily variation and annual changes influence is bigger. Find various factors of concrete temperature stress influence, summarizes and analyzes the basement environment temperature stress formed and the present situation of size, system studies the corresponding control measures, to expect success over control of temperature stress produced in the basement of the adverse impact on structure, promoting China's basement project quality problem of governance and raise the level of construction.The effect of ambient temperature analysis on the basement to consider when the ambient temperature changes, determine the most unfavorable studied wall temperature effect, and through empirical formulas and finite element linear elastic was calculated under the most unfavorable temperature load of wall structure effect, it is concluded that the wall inside the stress distribution law. Analysis seasonal temperature difference (thermal stresses of "Wang Tiemeng method" calculation formula )and air temperature pelter produce indoor and outdoor temperature different(finite element analysis method (FEM)),and thermal stresses in the distribution of long and change rules with wall long give a summary.By changing the boundary conditions and build the cross-section size analysis under the effect of environmental temperature on the overall structure. Analysis of different lengths, different the thickness of floor and wall, different wall heighth, different boundary conditions and different concrete strength and different temperature difference of wall and floor thermal stresses factors such as the influence of thermal stresses on the discussion area and the produce wall and floor distribution, and turns the soil in the basement of side wall protect the role of the analysis. Finally, from design, material, construction aspects analysis, combined with the engineering practice of the temperature cracks, reasons and solutions and measures for the future long-term project work to find new solving direction put forward new ideas.