Buried pipe analysis

[KeyboardKev]

If using a flowable fill/lean concrete mix for pipe bedding under deep burial, what is a proper value for the "soil modulus" used in burial calculations? I'm think it related to the modulus of elasticity of the bedding fill, but I'm not sure.

 

[stanier]

There are two componenets in the analysis of a buried pipe when it comes to soil moduli. The embedment modulus is what you are referrring to but one also takes into account the native soil modulus.

I suggest you download Australian Standard AS 2566.1 available from

http://www.standards.com.au

for a few dollars. The commentary alone is worth the price. There is a discussion there on deep trenches and the alternate design methods. Also there is information on the type of bedding/backfill to which you refer.

 

[Ron]

Assuming that your bedding material has a compressive strength somewhere between 500 and 1000 psi and is reasonably thick (8-12 inches), then the modulus value would be that of the flowable fill or lean concrete. This value will be somewhere between 250ksi and 500ksi.