SE-Ia Cowman
Well-Known Member
Sorry for the delay guys with winter shut down i have been out of the dirt work mood and in to mechanic mood.
First question compaction under the pipe.
the pipe was set on ground that met +95% compaction then we poured concrete under the pipe hence the blocks and wedges to keep at least .5' for concrete to flow under and around the pipe, forms were 12'' tall then we poured the mud stiff enough to push up aginst the pipe halfway up. Hard to put in to words but the whole lower half and .5' under the pipe is bedded with concrete. Then we used a jumping jack and packed the top half we had to have 2' covering the pipe before we could cross it with a sheeps foot. In sted of anti seep collors the use a sand diaphram it crosses the pipe in the middle of the dam 3'wide 15'long goes from 6' below pipe to 12' above the pipe then runs parallel with the pipe about 6' to the side down to the outlet channel. The engineers think if the water ever tunnels along side of the pipe it will filter down through the sand at the half way point and have a controlled path to the outlet and not wash out the dam.
Yes scrub the pipe is for normal rain water the emergency spillway has a 4% inlet section a 30' wide by 72' long control section and the rest is 2% outlet section. It is along the far end of the dam. With 12' of stage between the pipe and the emergency this pond will likely not see any emergency water for many years, engineer says 100 year flood but around here we have one of them every other year.
First question compaction under the pipe.
the pipe was set on ground that met +95% compaction then we poured concrete under the pipe hence the blocks and wedges to keep at least .5' for concrete to flow under and around the pipe, forms were 12'' tall then we poured the mud stiff enough to push up aginst the pipe halfway up. Hard to put in to words but the whole lower half and .5' under the pipe is bedded with concrete. Then we used a jumping jack and packed the top half we had to have 2' covering the pipe before we could cross it with a sheeps foot. In sted of anti seep collors the use a sand diaphram it crosses the pipe in the middle of the dam 3'wide 15'long goes from 6' below pipe to 12' above the pipe then runs parallel with the pipe about 6' to the side down to the outlet channel. The engineers think if the water ever tunnels along side of the pipe it will filter down through the sand at the half way point and have a controlled path to the outlet and not wash out the dam.
Yes scrub the pipe is for normal rain water the emergency spillway has a 4% inlet section a 30' wide by 72' long control section and the rest is 2% outlet section. It is along the far end of the dam. With 12' of stage between the pipe and the emergency this pond will likely not see any emergency water for many years, engineer says 100 year flood but around here we have one of them every other year.