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Abstract:

In the simulation analysis of mass concrete, thermodynamic parameters exert great influence on the calculation results. Existing thermodynamic parameters of concrete are mostly obtained from laboratory. However, the hydration heat reaction of concrete and the influence of surrounding environmental factors on concrete would inevitably change the performance of concrete, and there is a great gap between actual thermodynamic parameters and laboratory data, which would affect the accuracy of finite element simulation calculations. To obtain accurate thermodynamic parameters, combining with the measured data of the lower reservoir dam of Fujian Zhouning pumped storage power station, inversion analysis of the thermodynamic parameters is carried out, such as adiabatic temperature rise of concrete, surface heat dissipation coefficient, coefficient of linear expansion and elastic modulus, etc. Moreover, a three-dimensional finite element model is set up to calculate the temperature and stress field of a typical dam section. Then, the optimal solution objective function is constructed based on the calculation results, so as to obtain the optimal thermodynamic parameters. The results show that the thermodynamic parameters obtained by inverse analysis have a small relative error compared with the measured values, and show high accuracy. As to the lower reservior dam of Zhouning pumped storage power station, the actual adiabatic temperature rise is greater than the design parameters, the maximum temperature of concrete is 3°C higher than the design parameters, the coefficient of linear expansion has decreased by 0.6 compared with the design value, and the modulus of elasticity has increased by about 1.8 GPa. The rule of change of each parameter in this inversion is proved to be consistent with the actual situation, which can be used as a reference for similar projects.

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