Three existing 35m high prestressed concrete storage silos were to be demolished.  BWCE were engaged to carry out an assessment of the existing concrete structure for cutting a new access doorway in the wall of the silo to allow for removal of the demolished steel roof structure.  The concrete structure was assessed using a combination of FEA and traditional concrete stress calculations.  As can be seen in the video, during the explosive demolition of the roof structure, the new doorways also acted as pressure relief vents.