In 1946, Naoum Shebib built the Ali Baba movie theater in Cairo's district of Boulak.A thin reinforced concrete vault covers the huge interior space.
This vault which covers an area of 800 square meters (8600 square feet) is supported only by peripheral columns.
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The method used for the construction of the thin vaults was unique to Naoum Shebib.
Indeedt Naoum Shebib invented a method which consisted of building a vault-shaped earth mould on the ground, positioning steel rods on it and then pouring a thin layer of concrete over them thus coating the metal reinforcements.
Once the concrete had hardened, the vault was slowly lifted by a system of jacks to its final position which could reach up to 12 meters (40 feet) in height.
This method was patented under the name of “Voûte Chébib” (Chebib Vault).
For soils that could not withstand concentrated loads, Naoum Shebib designed a special and innovative type of raft foundation that distributed the load over a large area.
These raft-type foundations were constructed through a set of reinforced concrete thin shells in the shape of a hyperbolic paraboloid standing two meters (six feet) tall.
In order to build this innovative type of raft foundation, earth moulds were made in the desired shape, steel rods were added and concrete poured over them.
This raft foundation provided a large contact area and got its strength through the hyperbolic paraboloid form.