Earth loading on a sewer line 1

[noroc]

I’ve run into a situation where a PVC storm water line has to be installed in an area where the native soil is “muddy” with maybe a max. 100 psi E’ (soil modulus of elasticity) <br>I would like to use as bedding/backfill material 0.75” crushed rock.<br>The question is how wide the trench needs to be such way to prevent the crushed rock to be bushed away into the native soil and loose compaction?<br>Any formulas or real life experience?<br>Thank you<br>

 

[murph]

You have not provided much information on the soil characteristics, depth of burial, or any external loads.&nbsp;&nbsp;In poor soils,&nbsp;&nbsp;care should be taken that the trench is constructed safely.&nbsp;&nbsp;If you are concerned about migration of the granular backfill into the native soil, I would suggest using a geosynthetic fabric as a separator.

 

[nitpik]

You didnt indicate a size of pipe or distance to be traversed...a quick and dirty solution is to encase the pvc in steel pipe if it is just a relatively short crossing.

 

[msmith]

Get the UniBell PVC Pipe Assoc. Handbook of PVC Pipe which has a very extensive design method for burying PVC pipe. Available on-line at <A HREF="

http://members.aol.com/unibell/"

TARGET="_new">

http://members.aol.com/unibell/</A>