UNDERGROUND CHAMBERS

摘要

An underground chamber (10) has a wall element (12) defining and lying in a first plane (20) and having inner (16) and outer (18) skins separated by spaced ribs (20) spanning the gap between said skins and joined thereto. A top (22) also joins the skins and lies in a plane substantially perpendicular the skins and ribs. The ribs extend from said top to a level spaced from bottom edges (16b, 18b) of said skins, forming a slot or channel (26). Into this is fitted a stiffener (30) comprising a base (32) and upstanding flanges (34,36). The flanges are of a height, substantially equal to the separation of the bottom of said ribs from said bottom edges. The flanges are supported by stiffening webs (38) connected between said flanges and to said base. An alternative arrangement provides the stiffening under the base. Also, pockets (54) are provided for hanging furniture.