Coefficient of friction

[JaleelurRehman]

My client is asking for “ratio of friction angle at soil-concrete interface to the effective friction angle of soil” to be included in our soil reports. Please anyone explain isn't it the Coefficient of friction actually?

Jaleel Ur Rehman
Geotechnical Engineer
Osaimi Engineering Consulting Office, KSA

 

[Mccoy]

Jaleelur, the effective friction angle is related to soil-soil friction along a surface and is called phi' or φ'. Against other materials, soil has different angles of frictions, called delta or δ'.
In the European codes, against rough, cast in situ concrete δ' is equal to φ'_cv, that is φ' at constant volume or φ' at the critical state. against smooth, prefab concrete δ' = 2/3 φ'_cv, other values are available in the technical literature:

http://www.finesoftware.eu/help/geo...friction-factors-for-dissimilar-materials-01/

http://www.mccoy.it

 

[JaleelurRehman]

Thanks Mccoy. But coefficient of friction is same ratio (δ'/φ'cv) as we are already providing this to the client.

Jaleel Ur Rehman
Geotechnical Engineer
Osaimi Engineering Consulting Office, KSA

 

[Mccoy]

Thanks Mccoy. But coefficient of friction is same ratio (δ'/φ'cv) as we are already providing this to the client.

Then, either I'm missing the point, or there is a misunderstanding with the client...

http://www.mccoy.it

 

[GeoPaveTraffic]

I'm with McCoy, what is the question?

I've always used 2/3 phi for the friction between soil and concrete.

Mike Lambert

 

[killswitchengage]

the question is kinda obvious : δ=2/3φ if we take a simple default setting , so the ratio in this case is 2/3