Abstract: Surface thermal insulation boards are commonly employed in concrete dam projects in the alpine region of northwest China to prevent thermal stress-induced cracks in the dam structure. However, issues such as the detachment and loss of insulation boards can jeopardize the structural safety of dam during operations. In this study, an arch dam in the alpine region is used as a case study to analyze the impact of insulation board detachment on concrete. The analysis combines a thermal-structural coupling numerical simulation method with a statistical model based on displacement monitoring data. The numerical simulation results demonstrate that the temperature influence in the detachment area mainly occurs on the concrete surface. The maximum temperature difference is approximately 9 ℃, and the corresponding displacement difference of characteristic points reaches up to 2 mm. The maximum principal tensile stress on the concrete surface in the detachment area is 0.841 MPa. Moreover, the statistical model of dam body displacement confirms that the amplitude of displacement changes before and after detachment can reach 6 mm, aligning with the patterns observed in the numerical simulation results. The research findings provide valuable insights for investigating thermal insulation boards on concrete arch dams in alpine areas.

Key words: arch dam, thermal insulation board, thermal displacement, thermal stress, numerical simulation, safety monitoring, high and cold area