Inversion of thermodynamic parameters and optimization of temperature control measures for concrete dams in high altitude areas

Abstract

The meteorological environment in the high cold and high altitude area is complicated, and there are great differences between the design conditions and the actual conditions, which may increase the cracking risk of concrete under certain conditions. Therefore, it is necessary to conduct inverse analysis of the thermodynamic parameters and temperature field during the construction period, and optimize the temperature control measures to ensure the construction safety and quality. The whole process simulation analysis method of the dam and the measured temperature data during the construction period are used to comprehensively compare and analyze the differences between the indoor thermal and mechanical parameters and the actual parameters on site. By using the inversion temperature parameters and the actual pouring progress, the temperature control measures of the steep slope dam section are optimized by simulation analysis. The inversion analysis showed that the calculated value was in agreement with the measured value after the adiabatic temperature appreciation was adjusted to 27.5 ℃. When the final value of adiabatic temperature rise of secondary normal concrete is 35 ℃, the calculated value is the closest to the inverse analysis value. The comparison between design adiabatic temperature rise and inversion analysis shows that the early temperature of inversion is higher than the design value, but the final value is lower than the design value. The simulation result show that the maximum stress along river is 1.50 MPa and the safety factor is 1.64. The stress and safety factor in other areas are within the reasonable range, but the safety reserve of foundation strong confinement area and normal concrete bedding is slightly lower. On the basis of accurate inversion of thermodynamic parameters, combined with the result of simulation analysis, it is found that the temperature control measures of the foundation strongly confined area and the normal concrete bedding need to be further optimized, especially the maximum temperature should be further strictly controlled and the surface protection should be strengthened. The inversion of parameters and the feedback method of temperature stress field used in this paper can reflect the actual construction situation more accurately, and provide more reliable technical support for the optimization of construction standards and measures of mass concrete.

Keywords

mass concrete / temperature control / parameter inversion / temperature control measures optimization