Title: Deformation characteristics and a safety monitoring model of high arch dam affected by valley narrowing deformation
Abstract: Valley narrowing deformation was monitored during the first impoundment period of some high arch dam projects in China, which may affect the working behavior of dams. Dam deformation upstream was one of the most intuitive influences of valley narrowing deformation on arch dam, which makes dam safety evaluation difficult. In this paper, based on detailed monitoring data of a high arch dam project, the temporal-spatial evolution characteristics, and the mutual relationship of valley and dam deformation were analyzed. The influence of valley narrowing deformation on dam deformation was simulated by 3D Finite Element Method (FEM). According to the analysis results, an arch dam deformation safety monitoring model, considering the effect of valley deformation, was established in which the dam deformation was decomposed as water pressure, temperature, valley deformation, and time-effect components. Further, the typical process of valley deformation was analyzed using the proposed model and the decomposed components were separated. Research shows that the safety monitoring model can express the influence of various components on arch dam deformation comprehensively, and monitor the dam deformation quickly and accurately. The proposed model can be used to analyze and predict the arch dam deformation, and evaluate the dam behavior.