Deformation monitoring analysis of an RCC gravity dam considering frost heaving in an alpine region: a case study

This study investigates the use of a modified statistical model to quantitatively analyze and assess the current operation status of an RCC (Roller Compacted Concrete) gravity dam in an alpine region. Initially, combined with the measured temperature analysis and temperature field simulation results of a typical dam block, it is demonstrated that frost heaving data are essential to monitor dam crest deformation. The frost heaving factor is introduced using an engineering analogy method, and a modified statistical model considering frost heaving based on the Heaviside step function adaptive model is established. The analysis shows that (a) in the low-temperature season, the deformation near the dam crest is affected due to a wide range of negative-temperature zones; (b) the frost heaving component identified using the novel statistical model shows that the dam crest frost heaving deformation presents a variation law of periodic pulsed fluctuation and a ten-day cycle of hysteresis. The safety assessment of concrete dams crest without any insulation measures in alpine regions should thoroughly consider the displacement caused by frost heaving, which is highly relevant to improving the accuracy of dam safety evaluations over long-term service periods.