Experimental Study on the Impact-wear of the Concrete for Sabo-dam (II)

Abstract

This paper aims that we make clear the effects of some factors (such as the weight of the stone, the height of the dam, the angle of downstream slope so on) against the impact-wear of concrete surface caused by the sediment overflowing the sabo-dam. The results of experiments are as follows:
1), The relations between amount of the impact-wear on the concrete surface (M) and the weight of collisions (W), and between (M) and the falling height (H) are shown respectively by following equations M=aW^m, M=bHⁿ. In these case m takes 0.8-1.1 and n takes 0.8-1.9 depending on the materials of the concrete. Then, the amount of the impact-wear in proportion the kinetic energy of colliding sediment.
2), The relation between the weight of collisions (W) and the number of colliding times (N) which cause a certain amount of the impact-wear is shown the following equation, N·W^p=constant, p takes generally 0.8-1.1 (≈1.0). It shows that amount of the impact-wear are caused by the total weight of the sediment regardless of the size.
3), The ratio of the wear in the case of inclined to the holizontal place (R_M) will be estimated by the following equation, R_M=(1+Bsin²θ)cos²θ. θ is the inclination angle of the concrete surface, B is the proportional constant and takes 0.9-1.6 in this case.