Barcelona Metro - Line 9.
Sagrera Meridiana - Gorg

Barcelona Metro Line 9 is included in the Master Plan for Public Transport Infrastructure 2001-2010, running from the Airport to Badalona-Santa Coloma de Gramenet, with a length of 50 km and a total of 52 stations (30 shaft type, 17 cut and cover and 5 in viaduct).
The section Sagrera Meridiana - Gorg has a total length of 6,029 m that are distributed in 5,176 m TBM excavated and 853 m with cut and cover method. The works include 6 stations (Gorg, the Salut, Llefia, Bon Pastor, Onze Sagrera Setembre and Sagrera Meridiana), and intermediate slab who divides the tunnel section into two halves.

The tunnel is excavated with a TBM diameter of 12.06 m diameter and 10.90 m inner diameter, the thickness of the segment 40 cm. The tunnel dimensionaes allow, on one hand, running the stations and facilities auxilieres inside the tunnel and on the other, the superposed traffic through the execution of an intermediate horizontal slab.

As singular elements must highlight the Sagrera´s super shaft (For tunneling crossing with Line 4) and Soldevila's Street ventilation shaft.

Tunnel execution is performed with a shield EPB (Earth Pressure Balance). This type of TBM is mainly used when we are dealing cohesive soils, which is characterized by good plastic deformation, low internal friction angle and a low water permeability.

TBM characteristics are the following:

Ø cutting wheel	12'09 m
Ø front shield	12'06 m
Ø tail shield	12'03 m
Shield length	10'995 m
Shield length + back up	97 m
Maximum earth pressure	4'5 bar
Maximum advance speed	80 mm/min
Maximum cutting wheel speed	2'6 rpm
Propulsion cylinders	19 pairs
Maximum thrust	138.000 kN
Cylinders development	2.800 mm
Number of mortar injection pipes	10
Total installed power	6.190 kW

The stations are characterized by the depth to which they are executed as a result of the great tunnel depth, reaching mearby LLefià more than 50 m below the surface. The trace depths are motivated, on the one hand to avoid affection problems to some of the many underground works in the city of Barcelona, and secondly to minimize any potential settlement in the surface.

The stations typology is circular shafts of 26 m diameter and varying depths between 40 and 70 m. The constructive process was using concrete retainig walls or descending rings as the case.