Nowadays, UmbrellaArch (umbrella belt system) method has been developed under the name of tunneling methods arched methods in poor ground conditions.
The purpose of this method is to create a fortification shell around the tunnel excavation mirror without excavation in the tunnel mirror, and then provide progress by excavating under this secure shell.
In these excavations, it should be ensured that the normal section of the tunnel should be extended 50 cm outside in a progress of 3 meters. Umbrella pipes in the region of the application, the tunnel mirror around 30 cm intervals, concentrate and the inclination is 5-8 degrees up and up.
Standard dimensions for Umbrella Arch and equipment (Pipe, Ring Bits and Pilot Bits) are given in the table below.
|Product Code||Pipe Ø mm||inch||Ring Bit Ø (mm)||Pilot Bit Ø (mm)|