Extra meshes for deep industrial foundations

[Gourile]

It is customary to set extra reinforcing meshes for industrial foundations with depths more than, say, 1.5m(5ft). However only bottom mesh reinforcement in most cases is enough and sometimes even superfluous for carrying the bending moment. Is there any design or practice code to set these extrameshes, sometimes in number of layers, in this type of foundations?

 

[Ginger]

I fail to see why these extra sheets of mesh are necessary. Are they a mechanism for enhancing the carrying capacity of bolts in the floor in order to hold plant? Andy Machon

 

[Gourile]

Ginger
I saw these extra sheets of meshes on heavy melt shops, when high temperature with dynamic loads were to act on a very deep foundation. By deep foundation, I don't mean a pile or a pire, just a block of concrete with great depth in comparison to its plan dimensions. I suspect that extra weight needed for the foundation to compenste for dynamic loading, and extra layers of meshes for resisting high temperature gradient, either caused byhydration of cement or by operational conditions. I wondered if somebody up there's got the practical experience in this matter.