Monolithic dome

A monolithic dome (from Greek mono- and -lithic, meaning "one stone") is a structure cast in a one-piece form. The form may be permanent or temporary and may or may not remain part of the finished structure. Monolithic domes are a form of monolithic architecture.

The igloo may be the earliest form of monolithic dome. While it is constructed of blocks of compressed snow, these blocks melt and re-freeze to form a strong, homogeneous structure. The dome-like shape of the igloo exhibits the two major advantages of a dome-shaped structure: great strength, and good insulation. The strength is due to the natural strength of the arch, and the insulation is due to the minimal surface area of a spherical section.

The first modern monolithic dome structure was built in Provo, Utah and opened in 1963 as an ice skating rink. Called Turtle Reams after its 1967 conversion into a general store by new owner Paul Ream, the building stood until it was demolished in 2006 for new construction.

Turtle Reams was built by first creating a mound of dirt in the desired shape of the shell, an ellipsoidal section 240 feet (73 m) long, 160 feet (49 m) wide and 40 feet (12 m) high. The mound was then covered in a grid of rebar, to provide strength, and a layer of concrete approximately 4 inches (100 mm) thick. After the concrete was cured, the dirt was excavated through the doorways, leaving the roof standing in its place. The floor was then poured to finish the structure.

Today, monolithic domes are used in a variety of residential, commercial and industrial projects. Because of the strength, durability and economics, they are used to store large amounts of various commodities in the cement, fertilizer, agricultural, power and mining industries. Due to their structural integrity, they are used as the containment buildings at some nuclear power plants. Forms have been made using nearly every common structural material including air pressure supported fabric.

Modern construction differs significantly from the original concrete-over-dirt method. The current methods were developed by three brothers from Idaho: David, Barry, and Randy South. The first dome built using these method was constructed in April 1976 in Shelley, Idaho:

...
Wikipedia