GC: n

CT: The ultimate complexity of design and analysis of stresses is attained in arch and dome dams. These dams are thin, curved structures commonly containing reinforcement, either steel rods or prestressed steel cables the volume of concrete required is much less than for gravity and gravity arch dams, but the competency of bedrock in foundations and abutments to sustain or resist loads must be of a high order.
Arch dams are usually built in narrow, deep gorges in mountainous regions where access and availability of construction materials pose especially acute problems.
Arch dams are of two kinds.
Constant radius arch dams – commonly have a vertical upstream face with a constant radius of curvature
Variable radius dams – have upstream and downstream curves (extrados and intrados curves) of systematically decreasing radii with depth below the crest.
When a dam is also doubly curved, that is, it is curved in both horizontal and vertical planes, it is sometimes called a dome dam. Some dams are constructed with two or several contiguous arches or planes and are described as multiple arch or multiple dome dams.
Analysis assumes that two major kinds of deflections or dislocations affect the dam and its abutments. Pressure of water on the upstream face of the dam and uplift pressures from seepage beneath the dam tend to rotate the dam about its base by cantilever action. In addition the pressure of reservoir water tends to flatten the arch and push it downstream.

S: http://community.dur.ac.uk/~des0www4/cal/dams/conc/concf12.htm (last access: 22 December 2014)

N: 1. From French, from Latin intra, within + French dos, the back, Latin dorsum.
The interior curve of an arch.
2. The curved downstream surface of arch elements.

S: 1. http://www.finedictionary.com/intrados.html – Webster’s Revised Unabridged Dictionary (last access: 22 December 2014); MW – http://www.merriam-webster.com/dictionary/intrados (last access: 22 December 2014). 2. GDT.

SYN: soffit

S: GDT

CR: dam