Real thermal anti-cracking safety evaluation method for concrete dams considering spatio-temporal characteristics

Thermal anti-cracking safety evaluation is the foundation of the thermal cracking control. In this study, to overcome the limitations of traditional anti-cracking design methods, a method for determining the whole spatio-temporal real anticracking safety of dams is proposed. Dynamic analysis of anti-cracking safety in the whole process is carried out through key process curves of six factors, including concrete temperature, autogenous volume deformation, tensile strength, structural stress, structural allowable stress, and anti-cracking safety coefficient. Based on the theoretical development of dam concrete thermal anti-cracking control, the spatio-temporal temperature gradient control theory and the customized intelligent temperature control strategy for the whole construction process of concrete dams are formulated. The developed evaluation method was implemented in constructing the concrete dams of Xiluodu, Wudongde, and Baihetan. As such, the highest temperature in concrete was controllable, the temperature change was adjustable, and the temperature control measures were optimizable. Thermal cracking was not observed in the post-construction investigation. The results can provide a reference for the design and construction of similar projects.