Pipe Connection to Manhole
Pipe Connection to Manhole
(OP)
We have a proposed situation where we have a 18" perforated pipe at a depth of 12' and then a 36" storm drain directly above it at a depth of 5'. Due to proposed site conditions there is not a way to not have the pipes in this orientation.
Does anyone have ideas of how to connect these to a proposed 72" manhole? The one way I am thinking is to use an inside drop structure for the 36" connection.
Thanks
Does anyone have ideas of how to connect these to a proposed 72" manhole? The one way I am thinking is to use an inside drop structure for the 36" connection.
Thanks





RE: Pipe Connection to Manhole
Outside drop manholes are typically preferred. A drop pipe is typically specified for a sewer entering a sanitary manhole at an elevation of 24 inches or more above the manhole invert. Some jurisdictions allow storm sewers to enter with higher drops.
Inside drop connections are secured to the interior wall of the manhole and provide access for cleaning.
Due to the unequal earth pressures that would result from the backfilling operation in the vicinity of the manhole, the entire outside drop connection shall be encased in concrete.
Probably the best option is to use an outside drop for the 36-Inch and have the 36-Inch enter the manhole just above the 18-Inch.
In any case, you will have to have the approval of the local agency having jursidiction.
You will have to backfill with aggregrate. Due to the unequal earth pressures that would result from the backfilling operation in the vicinity of the manhole, the entire outside drop connection should be encased in concrete.
Here is a link to some examples:
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RE: Pipe Connection to Manhole
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Pipe Connection to Manhole
RE: Pipe Connection to Manhole
Richard A. Cornelius, P.E.
WWW.amlinereast.com