Investigation of hydrodynamic pressure on the upstream face of dam during an earthquake

Abstract

1. With longitudinal vibrations along the axis of the pool the dynamic pressure at the center vertical line of a rigid plane vertical wall located in a V-shaped canyon is 75% of the pressure on a vertical wall located in a rectangular canyon. The values of $$C = \frac{\sigma }{{k\gamma h}}$$ for the V-shaped canyon can be found from the graph 2a and b. Horizontally, the pressure is distributed uniformly. 2. The dynamic water pressure at the center vertical line of a rigid arch dam with double curvature in a V-shaped canyon differs from the pressure on a vertical wall only at the lower part, where, because of the reverse slope of the upstream face it increases by 30%. In the horizontal direction the pressure increases by 25% from the crown to the abutments. The above is true for the arch dams with double curvature which are geometrically similar, (or almost similar), to the tested model. For other shapes of the upstream face further investigations are required. 3. The V-shaped cross section of the canyon similarly decreases the magnitude of the dynamic pressure on an inclined wall. The rate of decrease depends on an angle of the slope and on the shape of the canyon. With an angle of 22°30' with the vertical the decrease could amount to 15%.