Sealing of concrete lined tunnel excavation - is achieved by double layer of plastics foil fused onto fixings and distance pieces enclosing sealed void

摘要

The sealing of a concrete lined tunnel excavation is effected by a layer of plastics foil (7) fused to fittings (2) which are nailed (3) to the concrete wall (1). The fixings (2) and foil (7) are surmounted by coaxial distance pieces (9) and a further sheet of plastic foil (13) is fused to those (9). The two sheets of foil (7,13) enclose a sealed void (14) and in between them is a parallel intermediate sheet of tangled fleece or webbing (11). USE/ADVANTAGE - sealing for concrete lined tunnel excavation is easy to fix and secure.