Anchor drain pipe along toe of stream bank

[drewnje]

I am working on a design to collect some low flow groundwater seeps entering a stream. My issue is that to drain to single location I will have to follow the grade of the stream and my pipe is going to have to run at the toe of the stream bank within the stream channel. It is not a large stream and is dry through most of the summer when construction is set to occur. The bottom of the steam is comprised primarily of bedrock with the banks being quite irregular and varying form bedrock to up to 12" of soil. I have resolved myself to having to anchor into the bedrock bottom and am looking for some guidance into how best to due this. I am working within a lot of constraints that are not typical (e.g. legal issues, permitting issues). The pipe is going to be over sized, per the client's request, and will be 3" in diameter and will never be full. Flow from all the seeps combined varies from dry in the summer to less than 5 GPM in winter. There will be approximately 370' of 3' diameter pipe running down the stream. Initially I just wanted to throw some stone over top of it to overcome the buoyancy and be done, that idea has been shot down. So what is the best way to anchor a pipe to an irregular bedrock surface, any thoughts?

 

[bimr]

It is hard to imagine that you would be allowed to install such a pipe in the stream bed. Have you run this past the regulators?

What is the purpose of collecting and combining the seeps?

 

[drewnje]

Yes, we have obtained an ARAP for this. This project makes very little sense, but must be completed as part of a legal settlement. Basically it is what happens when lawyers take a turn playing engineer.

 

[bimr]

Use a high quality pipe (ductile iron) and support it on concrete piers with rock anchors.

 

[cvg]

duplicate post

http://www.eng-tips.com/viewthread.cfm?qid=340467