Concrete Arch Dam´s Foundation Interception Range Analysis

There is big difference in the foundation size selection of the concrete arch dam considering the upstream reservoir water load, so the 3-D FEM is constructed with the typical high arch dam in 300 m class in this paper, to analyze the displacement and stress under the condition that foundation depth and left and right banks foundation size are fixed, with the upstream and downstream foundation size changing, and the condition that the foundation depth, left and right banks and upstream and downstream foundation size take the same value and increased correspondingly. Analysis shows that: (1) when the water pressure only loads on the dam, the stress and displacement tend to be stable with the increase of the foundation size. (2) considering the upstream reservoir basin water load, the stress tends to be stable with the foundation size increasing, the displacement tends to be stable with the increase of the upstream and downstream foundation size under the condition of the foundation depth and left and right banks foundation size are fixed, while the displacement can´t tend to be stable under the condition of the foundation depth, left and right banks and upstream and downstream foundation size take the same value and increase correspondingly. (3) the actual foundation size is limited, if the foundation depth and left and right banks foundation size are fixed and taking the same value and no more than 40 times of the dam height, the displacement and stress of the dam has been able to meet the engineering precision or achieve stability when the upstream and downstream foundation size select 5 - 10 times of the dam height.