Cylindrical structure made up of rectangular elements

A tight and/or thermally insulated tank (1) comprising a sealing barrier and/or a thermally insulating barrier, said sealing barrier and/or said thermally insulating barrier having a cylindrical shape and comprising a vertical wall (3) and a bottom wall (2), said vertical wall being made up of a plurality of vertical faces (5), said bottom wall comprising a plurality of rectangular pieces (8) distributed in sectors (4) which are rotated images of each other, each sector comprising a plurality of said adjacent rectangular pieces (8), characterized by the fact that said bottom wall has the shape of a regular polygon whereof each side (6) corresponds to one of said sectors and one of said faces, the edges of the rectangular pieces of one sector being respectively perpendicular and parallel to the side of the polygon corresponding to said sector.