Back Analysis Of Thermal Parameters Of Hydraulic Concrete Based On The Response Surface Technology

Inverted siphon structure is encountered in the water near the elevation of the plane at the same time,in order to solve the phenomenon of its smooth flow of the construction of the overpass hydraulic structures.According to the definition of mass concrete,belonging to the mass concrete structure.As the hydration heat causes the internal temperature of the structure is higher than the outside,which will form a larger temperature difference,According to the mechanism of concrete temperature cracks,due to excessive temperature difference will lead to concrete tensile stress exceeds the allowable range,resulting in cracks.Crack development will not only affect the safety and durability of buildings,but also limit the economic benefits.To carry out a true and accurate structural simulation analysis is currently the goal pursued by a large number of scholars.The research shows that the simulation analysis of mass concrete structures,in which the accuracy of the relevant thermal parameters directly affects the trueness of the temperature field.Because of its related thermal parameters are usually obtained through experiments or experience,and the actual situation there is a big difference.Therefore,in order to achieve the accuracy and authenticity of the simulation analysis,a more accurate and reasonable thermal parameter needs to be analyzed backwards to prevent cracks from occurring or effectively control the harmful development of cracks.The main work of this thesis is:(1)According to the calculation theory of the finite element method of temperature field,the finite element model of the concrete obtained by experiment and experience is used to analyze the temperature field based on the finite element analysis software ANSYS.(2)Based on the measured temperature data measured by inverted siphon structure pouring construction,the corresponding display function expression is fitted by the response surface technology and the concrete thermal parameter,and then the best thermal parameter value(3)According to the parameters obtained by the back analysis,simulation and analysis of temperature field in the process of structure pouring.The main purpose of this paper:It provides more accurate parameters for the transient temperature field analysis ofinverted siphon so as to provide reference for reasonable construction and crack control of inverted siphon.The main conclusion of this paper:Through the analysis of the temperature field shows that the internal temperature of concrete structures higher than the external temperature,rapid heating,cooling slower.Structure inside and outside easily form a larger temperature difference,prone to cracks,should take the necessary measures to crack prevention and control.Through the analysis of the temperature field,it can be seen that the internal temperature of the concrete structure is higher than the external temperature,and the temperature rise is faster and the temperature decrease is slower.Through the analysis of the stress field,it can be known that due to the large heat production of hydration in the early stage of pouring,the tensile stress is large,and cracks are prone to occur.Therefore,necessary measures should be taken to control the cracks.