Research On Related Problems Of Temperature And Stress Control Of Mass Concrete

With development of economy and engineering technology, Water conservancyinfrastructure of China are developed rapidly and mass concrete is widely used inengineering. Due to its pouring huge volume, complicated construction conditionsand the uncertainty of external factors, large thermal stress of the concrete oftenappears at the construction and operation period. When the thermal stress exceedsconcrete tensile strength, temperature crack will appear. It can affect the appearanceof the structure and even normal safe operation of the structure.This paper expounds the mechanical characteristics of mass concrete，the causesand the characteristics of thermal stress. The research of temperature and thermalstress control for mass concrete at home and abroad also are summarized. By usingthe finite difference algorithm with high precision and efficiency, temperature fieldand humidity field of mass concrete are simulated and parameter is determined byinversion analysis based on genetic optimization algorithm. The last, the temperaturefield and stress field of mass concrete are simulated by using the theory of finiteelement. For the temperature and thermal stress distribution and variation rule underdifferent conditions, the effective suggestions for temperature and thermal crackcontrol of mass concrete are concluded. The main research results of this paper can besummarized as follows:1. Based on the equation of temperature and humidity field for mass concrete,the one-dimensional, two-dimensional and three-dimensional finite difference formatwith high precision and efficiency are concluded. Through the slove for projectexample, it’s proved that this method can solve temperature and humidity fieldeffectively.2. For the uncertain of concrete humidity field parameter, the least squaresmodel of inversion based on measured data for concrete humidity field parameter isput forward and sloved by using the theory of genetic evolution. Through thecontrast with experimental data, it’s proved that genetic evolution theory can solvethe inversion problem of the humidity field better. 3. The temperature and thermal stress field distribution of mass concrete atpouring period are analyzed by using the finite element theory and the results havegood agreement with the measured dates. The feasibility of the method is alsovalidated. On this basis, this paper analyse the various working conditions of massconcrete and obtains temperature and thermal stress distribution and variation ruleunder different working conditions. It can provide certain references for thermalcrack and control for mass concrete.Finally, the research results of the paper are summarized and the problems whichneed to continue or not solved are prospected.