Temperature monitoring experiment and numerical simulation of the orifice structure in an arch dam considering solar radiation effects

During the concrete pouring of arch dams in the high-temperature season, solar radiation significantly influences the surface of concrete pouring blocks. In this study, optical fibres were embedded throughout the pouring block of the Baihetan arch dam. Furthermore, a temperature gradient monitoring test for surface concrete of the floor and sidewall of the orifice was carried out in the high-temperature season to obtain the actual temperature of the orifice concrete. For the convenience of calculation, the heat flux caused by solar radiation heat is converted into air temperature. The solar radiation heat is regarded as the virtual air temperature increment, which is superimposed with the measured air temperature to form a comprehensive equivalent air temperature. Taking the comprehensive equivalent air temperature as the third boundary condition and considering the influencing factors, such as the pouring schedule, water cooling, and ambient temperature, this study uses finite element software to simulate the temperature field during the construction of orifice concrete. The results show that solar radiation heat has little influence on the concrete temperature in the middle of the pouring block. After the influence of solar radiation heat is considered, the accuracy of the finite element model of the orifice pouring block is significantly improved, and the influence of solar radiation heat on the floor concrete is smaller than that on the sidewall concrete.