Statistical modelling for high arch dam deformation during the initial impoundment period. Issue 12 (24th September 2020)

• Record Type: Journal Article
• Authors: Hu, Jiang; Ma, Fuheng
• Is Part Of: Structural control and health monitoring. Volume 27:Issue 12(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-09-24
• Subjects: clustering -- dam -- initial impoundment period -- principal component analysis -- structural health monitoring -- time‐dependent effect; Structural engineering -- Periodicals; Structural control (Engineering) -- Periodicals; Automatic data collection systems -- Periodicals; Detectors -- Periodicals; 624.17
• DOI: 10.1002/stc.2638
• Languages: English
• ISSNs: 1545-2255

Abstract

Summary: Although statistical models are efficient in most cases to analyze concrete dam displacements, these models are built on several hypotheses, leading to uncertainties especially for special periods. The special statistical models, improving estimations of the non‐stationary thermal and the non‐monotonic time‐dependent effects, are proposed for the displacements of high arch dams during their initial impoundment periods in this paper. The hierarchical clustering on principal component analysis is developed to divide thermometers into groups and to choose representative thermometers or identify major principal components on measured temperature data to represent the non‐stationary thermal effect on dam's displacements. The non‐monotonic formula for the time‐dependent deformation, emphasizing the creep and its restoration of dam concrete and its surrounding rock, is derived and further simplified when the reservoir water level exhibits an evident periodicity. Then, two improved statistical models accounting for these non‐stationary thermal and non‐monotonic time‐dependent effects are proposed. The proposed statistical models with clear physical meanings are applied to investigate the measured displacements of the Xiluodu arch dam. Model performance comparisons indicate that the proposed models have significant improvement in fitting precision and prediction ability over the traditional and more recent models. Model results confirm the influence of reservoir thermal stratification and concrete temperature rise on the thermal displacement, and the non‐monotonic effect on the time‐dependent displacement. The proposed models yield to a better identification of the deformation mechanism for high arch dams during their initial impoundment periods.