AN UNDERGROUND ROADWAY SUPPORT
An underground roadway support comprises interconnected side-by-side arch sections (20, 21, 22) each constituted by a plurality of interconnected panels (23, 24, 25). Each panel comprises a plurality of arch sections butted and coupled together, the panel being of rectangular configuration and having on two opposed sides formations adapted movably or adjustably to engage complementary formations on corresponding panels of adjacent arch sections to provide mechanically flexible connections therebetween. The formation on one side of a panel is a channel (31) open outwards of the panel, while the formation on the other side of the same channel is a box section (32) adapted to engage within a channel formation of an adjacent panel to form, in effect, a knuckle joint thus to permit joined panels, and consequently joined arch sections, to accommodate earth strata irregularities or variations.