Thank you very much, research which I made actually showed this result but I only explained it by rigidity but I always thought that there was another reason can be the stress field which creates a bulb of pressure like you say it .

in any event, I thank you for the answer.

Hi...the relation between the building stiffness and the tunnelling-induced deformations depends on the building weight.

Thank you

A good reference is the Jan Niklas Franzius thesis:

http://www3.imperial.ac.uk/pls/portallive/docs/1/985903.PDF

The proposed approach is wide used into the settlements estimations.

Thank you very much.