Halakatevakis and Sofianos  investigated Hoek-Brown criterion analytically through an extended plane of weakness
theory and validated it with experimental evidence on physical specimens.
We present below a case of a 37 year old man with SCC of the left forefoot, which spread through a natural plane of weakness
in the dermal-epidermal junction as a complication of the congenital weakness in the area resulting from EB.
That, combined with the geometric notch at the root of the head, creates a plane of weakness
in the rivet.
The first break occurred in a crystallographic plane of weakness
close to the point of attachment.
Halakatevakis and Sofianos  investigated the Hoek-Brown criterion analytically through an extended plane of weakness
A construction joint occurs when concrete pouring is stopped for 30 minutes or more; a control joint is a deliberate plane of weakness
to control the location of cracks that will occur; and expansion joints allow space for the concrete to expand and contract with temperature changes.