Beurteilung der Setzungen bei EPB-Vortrieben der Metro L9 Barcelona

Assessment of settlements at EPB drives of Barcelona's metro line 9.

For the construction of the 50 km long Metro Line 9 in Barcelona up to five earth pressure balanced shields have been used at the same time. Along 13.6 km the tunnel is excavated with an excavation diameter of 9.4 m and on a length of 27 km with a diameter of 12 m. Further sections are a 4 km long viaduct and 6 km of tunnels in cut and cover or conventionally excavated tunnels. First sub-sections of the new metro line are in service since December 2009. The advance of tunnels below urban areas requires an intensive preparation and control of the machine advance parameters as well as an intensive topographical and geotechnical monitoring programme. In the present article procedures for the preparation and control of an EPB advance are shown. Main focus is set on the machines working pressures and the resulting ground movements. The positive influence of the shield gap injection will be pointed out. For the analysis and evaluation of the settlements for the advance in soil, the so called "efficiency" will be introduced.