Dynamic module Es,dyn 2

[jb66]

Does anyone know something about dynamic module Es,dyn used for design of footing of wind energy plant? I´d like to know what is relation between Es, stat and Es,dyn.
Thanks.

 

[AlohaBob]

May I venture guess?
Static and dynamic modulus of elasticity - soil?

 

[jb66]

Thanks to AlohaBob,
you are right of course but I´d like to know how can I calculate Es, dyn or how can I determine its value.
Do you know?

 

[dbuzz]

Do you mean the static and dynamic shear moduli of the soil, G and G'? Unfortunately the dynamic modulus can't simply be inferred from the static modulus. It needs to be determined by laboratory test (resonant-column tests) or by in situ test (shear wave tests).

Static shear modulus
G = Es / 2(1+u)
where
Es = elastic soil modulus
u = Poisson's ratio

Dynamic shear modulus (from in situ test)
G' = p * Vs^2
where
p = soil density
Vs = shear wave velocity

 

[lebihan]

thank you for this question, i would be pleased to know the answer too

 

[AlohaBob]

I would follow dbuzz for a quick estimate and assumptions for understanding. Then further develop my research and design for the foundation. Eventually, you need soil tests to refine your values and be site specific. The foundation design for dynamic loading equipment needs compatability with the soil dynamics.

I hope this leads you in the right direction.