Armfield Instruction Manual
30
upstream water level should be stabilised 25mm below the dam crest; the
downstream level about 12mm above the bottom.
After the dam segment has been formed, water is first poured into the downstream
pool. Only after it is full should the upstream pool be filled. The rate of filling should
be slow. Otherwise the dam segment can easily collapse.
When the upstream water level is stabilised, needles with dye are inserted along the
upstream slope (next to the transparent side of the tank), the first being fixed
immediately at the water surface. The procedure to be followed in visualising the flow
lines construction of equipotential lines and calculation of seepage rate, is the same
as described in
Exercise A - Seepage Underneath A Sheet Pile Wall
.