Analysis of nine years of safety monitoring data from a roller-compacted concrete gravity dam in a high-altitude cold region

Long-term monitoring records from roller-compacted concrete (RCC) gravity dams in cold regions are scarce, although freeze–thaw cycling and large seasonal temperature ranges act there together with hydrostatic loading. This study analyzes 9.1 years of daily records (2016–2025) from 190 instruments on a 71 m RCC gravity dam in Xinjiang, China. Correlations are reported with seasonality controls and a significance criterion that allows for serial correlation, and the monitored changes are related to the sliding stability of the dam. Maximum downstream displacement is 18.71 mm. Its seasonality-controlled association with reservoir level is moderate (partial r = 0.26–0.58), and its multi-year baseline, after rising by about 3–4 mm over 2017–2021, has not risen since. Foundation uplift head stays below the reservoir level, decreases downstream and shows no upward trend, and no monitored change points to reduced sliding stability. Concrete strain follows local concrete temperature (raw r = 0.82–0.94). Stresses estimated with a code-specified modulus, no material tests being available, are order-of-magnitude values (1.1–3.7 MPa compression), and one tensile strain excursion is flagged for inspection. The annual response is reversible, and no monitored quantity shows cumulative deterioration; surface freeze–thaw damage is beyond the reach of the embedded instruments.