Waterproof layered concrete tunnel lining - has sliding sheet and joined pumped concrete layer on sprayed jointless layer

摘要

The support practice embodied in the New Austrian tunnel-building system is used for a waterproof tunnel cladding in double-skimmed form. The external vaulting is applied as a jointless layer of waterproof sprayed concrete, with 1.75 volume per cent of steel fibre additive, on an intermediate layer of sprayed concrete without fibre. The internal vaulting of dimensions according to static requirement, is made from shattered pumped concrete, with abutting joints, and separated from the external one by a sliding layer of cohesive material or thin foil. The steel fibre concrete is smoothed with a fibre-free sprayed concrete layer.