How is lift-slab construction done?
This is a system that involves placing the foundation, erecting columns with special lifting collars, constructing slabs one on top of the other on the ground, lifting the slabs to their respective positions with hydraulic jacks located on top of the columns, and finally connecting the slabs to the columns by the collar device. Slabs were originally lifted one by one. In a later development a system was devised for lifting them as a group and dropping off one slab at each floor level.