is a portion of a pile, which protrudes beyond the nominal diameter of the pile. This occurs when piles are bored through strata of soils with differing density. Bulging occurs when good practices are being observed.
The expanding of a portion of the body of a drawn shell below the top or neck.
The process of increasing the diameter of a cylindrical shell (usually to a spherical shape) or of expanding the outer walls of any shell or box shape whose walls were previously straight.