Use of drill injection anchors made from cold-rolled steel having longitudinal channels open in the region of the drill crown for rinsing and injecting cement as flat reinforcements for tunnel roofs

摘要

Use of drill injection anchors (1) made from cold-rolled steel having longitudinal channels open in the region of the drill crown (2) for rinsing and injecting cement as flat reinforcements for tunnel roofs is new. The drill injection anchors are overlapped in the tunnel direction and are surrounded by a pressing body (7) for cement injection. Head sections of the pressing bodies on the drill crown side lie in the region of the subsequent advancement of the tunnel. Preferred Features: The head sections extend to the length of 1.5-2 times the tunnel diameter in the tunnel advancement.