For example, those single taxpayers with $5,000 of Social Security benefits in the example above would see their marginal tax rate on nonâSocial Security income boosted by 50 percent if their modified AGI was between $25,000 and $30,000 and by 85 percent if their modified AGI was between $34,000 and $36,000.
Three types of vault were commonly used: the barrel-vault, the groined or four-part vault, and the dome. The barrel-vault was generally semi-cylindrical in section, and was used to cover corridors and oblong halls, like the temple-cellas, or was bent around a curve, as in amphitheatre passages.
The simplest kind of vault is the barrel vault (also called a wagon or tunnel vault) which is generally semicircular in shape. The barrel vault is a continuous arch, the length being greater than its diameter.As in building an arch, a temporary support is needed while rings of voussoirs are constructed and the rings placed in position. Until the topmost voussoir, the keystone, is positioned, the vault is not self-supporting.owever, when the vault is built above ground, various replacements are employed to supply the needed resistance. An example is the thicker walls used in the case of barrel or continuous vaults. Buttresses are used to supply resistance when intersecting vaults are employed.