EMPERICAL METHOD FOR ADOPTING THE LENGTHS OF NOF ON BOTH THE FLANKS OF A DAM

VT LONDHE NOVEMBER 1987–JUNE 1989

It has been generally observed that the water overflowing the crest of a dam drags by suction effect from either side and underneath whatever is available to it on both the flanks from upstream. Hence, it has empirically been decided that the length of the NOF portions which has to be kept on both the flanks should be such that the upstream wraparound slopes do not interfere in any way with the portions marked in red in the sketch below. The quadrant portions marked in red are drawn in such a way that the radius is equal to the height of water above the crest and the center is at the junction of the training walls with the crest.