| 摘要 |
Construction element for creating a tunnel, comprising a first, incompressible layer (6) of concrete and a second, compressible layer (7) fixed to the first layer (6) so as to form a one-piece prefabricated construction element designed to be incorporated into a tunnel section during the creation of the tunnel, the second layer (7) having a plurality of devices (8), each having a solid body (9) incorporating an empty space (10). |
