Research on the mechanical behavior law of local damage of insulation board during the operation period of high arch dams

The local damage to thermal insulation materials will affect the operation safety of concrete structures and even lead to the risk of cracking. Considering the relatively large thickness of the dam and insulation board , this paper proposes an equivalent simulation method for concrete extruded polystyrene (C-XPS) composite structures. It establishes a three-dimensional refined model to simulate the displacement and stress changes of the dam body before and after local damage of insulation materials under thermal solid coupling. The model considers the inversion values of fundamental dimensions and linear expansion coefficients, measurement point positions, and structural corridor. At the same time, according to the actual situation of the insulation board material damage during the operation period of the concrete arch dam , the monitoring data analysis is used as verification. The calculation results indicate that the equivalent C-XPS composite material structure simulation can effectively simulate dams' temperature, displacement, and stress changes after damaging the insulation board. After the insulation board is damaged, the temperature mainly causes significant changes in the surface temperature of the dam, while the internal temperature is relatively stable. The radial displacement of the dam suddenly rises in a short period and then returns to stability. The stress generated by temperature will not cause the dam to crack. This study provides valuable guidance for the safety evaluation of arch dams after partial damage to insulation plates.