keyways or steps to prevent the circumferential prestressing from sliding up the dome surface upon completion of the placement of all circumferential and or radial reinforcement shotcrete can then be applied manually or by automation over the outside reinforcement to provide the desired cover a final paint epoxy or other type of sealing material may be applied over the shotcrete shell in the preferred embodiment the sequence of construction resulting in a dome structure according to the present invention is as follows a base 10 is constructed with or without an integral footing 12 as required regular or prestressed reinforcing rods 14 and 19 can be used to strengthen the base thereafter the membrane is installed and sealed in slot 18 in the base the ring 26 is then positioned centrally above the base and radial prestressing members such as radial prestressed wires 20 are extended loosely between the base and ring the prestressing wires are connected to the footing on one end and on the other end to the ring they are fastened to the ring by wedge anchors 28 the next step involves the inflation of the membrane tailored to form the desired shape within the radial prestress wires which applies tension to the radial prestress wires and provides the desired form which in the preferred embodiment is elliptical in shape rigidifying materials such as shotcrete is then applied both above and above the membrane embedding the membrane and radial prestressing wires therein once the shotcrete has partially cured the air which caused the membrane to expand to the desired range is released the concrete is therefore placed in compression and a self sustaining dome is formed the membrane is not removed but remains imbedded in the concrete forming a seal or waterstop and preventing the.