…we have derived the limit acceleration of progressive collapse of a high-rise building from its top. We have found that the theoretical upper limit of acceleration of falling mass, omitting any resistance of columns, and assuming that all the falling mass hit the lower floors, is one third of the gravitational acceleration. When assumed that half of the falling mass fell outside the building perimeter, the limit acceleration is one fifth of the gravitational acceleration. The acceleration limits were derived independently from both pertinent laws of mechanics ... Read even more
