Secondary Safety Monitoring Indexes for Displacement of Lijiaxia Arch Dam Based on Structural Calculation Method

As one of the most important concrete arch dam of upper reaches of the Yellow River, Lijiaxia concrete arch dam is 155 meters high. The reservoir, which capacity is 1.65 billion cubic meters, began to store water at Dec 26, 1996. According to the loads occurred on the dam and its foundation, safety monitoring indexes can be established to assess condition of the dam and to predict probable loads the dam can bear. Because a displacement observation system of Lijiaxia concrete arch dam was established and the continuity and reliability of observation data are proved, secondary safety monitoring indexes for displacement of Lijiaxia concrete arch dam are calculated and analyzed in this paper. In this paper, three-dimension nonlinear finite element model of Lijiaxia arch dam, considering some major faults and foundation treatment measures, is established. The stress, strain, positions and scopes of yield zone and failure zone of the dam under different critical load conditions are obtained by structural calculation method, and the secondary safety monitoring indexes for displacement of Lijiaxia arch dam are determined. By analyzing the indexes, safety operation of the dam can be ensured. This paper also provides an effective way to determine other kinds of safety monitoring indexes.