Tunnel tubbing liner grout injection hole sealing - has non-return valve in hole with bow and strip supports to maintain sections

摘要

Tunnel tubbing liner grout injection hole sealing system for use in water-bearing ground is characterised by non-return valves placed in all grout holes so as to prevent the grout or water or mortar from running back in whilst at the same time not impeding the grout injection operation. The lip valve suggested for this duty should have a roof shaped support bow (4) in the opening to keep the lips (3) of the valve in the prescribed position. This is assisted pref. by a strip (5) at right angles to the bows to maintain the opening section. Sealing should be provided by a rubber hose cuff seal (2) drawn over the cylinder (1) and reinforced in the lip region.