| Webster's Online Dictionary |
| Expressions | Domain | Definition | |
| Hercularc lining | Mining | A German method of lining roadways subjected to heavy pressures. It consists of a closed circular arch of specially shaped precast concrete blocks. The blocks, which are wedge-shaped, are made in two sizes for each lining and erected in such a way that alternate blocks offer their wedge action in opposite directions--the larger blocks toward the center of the roadway and the smaller outward. This arrangement gives a double-wedge effect so that part of the lateral pressure exerted by the strata on the lining is diverted axially along the roadway. (references) | |
Source: compiled by the editor from various references; see credits. | Top | ||
