How to reduce the value for cohesion

[kokfann]

In Eurocode7, there are 3 types of Design Approach (DA) to calculate the ULS for GEO.
In DA1.2 and DA3, the angle of shearing resistance,? have to be reduced. For example, with ?=30, it needed to be reduce to arctan(tan30/1.25) = 24.8.

The cohesion,c' have to be reduced in DA1.2 and DA3. The question is how? Thanks!

 

[Mccoy]

kokfann,
the original gamma(m) factor (partial FOS) for c' would be 1.25.

It can be changed though, according to specific national requirements.

In Italy, for example, initially it was the same as EC7, then recently it was increased to 1.4, same as Cu.

It makes sense to me, since statistical variability in c' and Cu is pretty much the same.

Also, do not let's forget that nominal or 'derived' values of parameters must be transformed to 'characteristic' values before the gamma-factors are applied.

 

[kokfann]

thanks Mccoy, but i need the method. but anyway just to share with others, i just got it. it's c_d = c_k / gamma_c

silly me....silly me...