Procedure for driving tunnels and roadways - secures driven out section between shield end and final support by advancing shield tail spragged against wall

摘要

In the procedure for driving tunnels and underground roadways by means of a driving shield to secure the driven out section between the end of the shield and a final support a shield tail is brought in to support its exposed roof and walls. When the roof and walls are supported by the final support the shield tail is withdrawn in direction of drivage. The shield tail consists of a number of parts and those facing the roof of the driven out section are spragged against the walls (19) of that section before or during setting of support units in the shield tail. The shield tail is spragged against the driven out section by the set spragging support units (20, 30). when the shield tail is advance in direction of drivage these are tensioned against wall (19) of the driven out section.