| 摘要 |
PCT No. PCT/GB89/00527 Sec. 371 Date Jan. 17, 1991 Sec. 102(e) Date Jan. 17, 1991 PCT Filed May 16, 1989 PCT Pub. No. WO89/11566 PCT Pub. Date Nov. 30, 1989.An erosion protection unit (7), comprising a tetrahedral frame comprising six outer elongate members (9) arranged in the outline of a tetrahedron, and a triaxial central strut arrangement (11) comprising three struts (13, 15, 17) arranged mutually perpendicular to one another and passing through the geometric center of the tetrahedron, such that each outer member is braced by a strut passing from its center to the center of a second opposite outer member. |
