Investigation of temperature rise after arch closure based on monitoring and numerical analysis: A case study of Baihetan arch dam

Baihetan Arch Dam is the world's first 300 m grade ultra-high arch dam using low-heat cement concrete. The hydration characteristics of low-heat cement concrete, especially the effect of temperature rise after arch closure on the temperature field and the working behaviors of the arch dam, are not yet fully understood. This paper investigates the temperature field of the Baihetan arch dam based on the monitoring data and numerical analysis. The monitoring data indicates the temperature rise after closure is about 2.4-7.5 C-degrees inside the dam body until May 2023. Although the annual temperature rise falls yearly, the temperature field has not reached a stable status. The numerical simulation demonstrates that for a super high arch dam like Baihetan, the majority source of the temperature rise after closure is the residual hydration of concrete. Meanwhile the heat backwards from the foundation and the external environment also contribute to the rise inside the dam body near the foundation and the body of small thickness to some extent. The good agreement between monitoring and calculated temperatures verifies that the residual hydration function and parameters adopted can reflect the hydration characteristics of the low-heat cement concrete, and the simulation scheme is practicable to be applied on similar constructions to predict the temperature field.