Upgrade of railway tunnels along connection lines with the new railway line AlpTransit of San Gottardo. The upgrade involves 22 railway tunnels for a total length of 18,2 km.

Notably, along the Milan-Luino line, is provided for the adjustment to the shape PC80/P140 (P.M.O. n°3) for the following lines:

Sesto Calende – Busto Arsizio.

The Line 4 is a new underground line under construction in Milan, part of the city metro system and it will be the second driverless line in the city of Milan The line will be 15 km long with 21 stations.

Alpina is in charge of designing preliminary and detailed design of the structural and geotechnical works for 8 underground stations, 3 inter-stretch building structures, 3 tunnels, 1 bridge and n the design assistance on site during construction.

The works were engineered in loose soils below the water table, alongside the existing buildings or infrastructures in the city centre. The underground main structures are built using bottom-up procedures below water table or using combined bottom-up and top down techniques for high excavation depths (up to 30 m, 20 m below the water table).

Alpina carried out the final design of the structural and geotechnical works of five stations of the Milan Metro Line 5, as well as the tunnels of the Garibaldi junction. In particular engineering designs were provided for the Isola, Garibaldi, Monumentale, Cenisio and Tre Torri stations, all of the underground works of the Isola and Monumental stations for a total of about 1,8 km of tunnels in the urban area, in loose soil below the water table, alongside buildings or existing infrastructures such as the 70 m high tower at the AC Hotel.

As part of the project for the new Lyon – Turin high speed railway, this contract concerns the construction of the Avrieux shafts, a part of the safety site, a section of the base tunnel towards La Praz and the tunneling machinery chambers of the future section 05.

The main works concerning the shafts are broken down into two parts:

• Part 1 – Avrieux Shafts (n. 4 ventilation shafts);
• Part 2 – Tunnels at the bottom of shafts (connecting gallery, room at the bottom, ventilation tunnel, heads of the smoke shafts, smoke shaft at the intertube gallery). The basic solution involves the construction of four shafts of 4,26 m internal diameter and 5,20 m excavation diameter dug at Raise Boring aligned in pairs on two rows spaced by 2 diameters.
• The 4 shafts have a depth of about 500 m each, from the platform of Avrieux to reach the room at the bottom of the wells.
• The room at the bottom of the shaft is connected to the ventilation tunnel.
• The inter-distance of the shafts is 12,5 m with the exception of the two shafts at the entrance of the ventilation tunnel, which are arranged at 20 m distance to ensure the maneuvering area of the machines.
• The installation of the shafts must be compatible with the size of the opening of the ventilation plant at surface in order to directly open the 4 shafts in the future central platform. The constraint to be met includes the requirement to enclose the shafts in a rectangular area with footprint 28,0 mx 18,39 m.
• The excavation section of each of the four shafts is 21,24 m².

The construction method chosen consists of 4 main phases which are as follows:

1. Dig a pilot hole from top to bottom in about 15 inches (RVDS directional drilling).
2. Bore up to 5,20 m in diameter with the Raise-Boring method.
3. Install a temporary support from top to bottom once the bore is finished.
4. Final coating of the shaft from the bottom to the top with slippery or creeping formwork.

A jet-grouting soil consolidation treatment is necessary before RBM digging to ensure shafts wall stability.

The cuttings produced by boreholes fall at the base of the shaft in each sector of the basic chamber, divided into independent sectors by temporary partitions.

The construction of the concrete final lining is done by sliding or creeping formwork, from the bottom to the top. The presence of a seal between the coating and the solid structure significantly reduces the transmission of the weight of the coating to the rocks by friction. For this reason, in order to provide support to the coating, which would otherwise be suspended to the top of the shaft, 12 precast concrete hemispherical supports every 10m are anchored to the solid structure by HA32 bolts, 2 m long, inclined by 20°. The execution of the shafts is done in a soundproof acoustic shed able to limit the noise nuisances within the limits set in the NRE.

The Lyon–Turin Base Tunnel is a key element of the trans-European Network for passengers and freight, the West-Eastlink of Corridor V, connecting Lisbon to Kiev.

The twin tube 57 km Base Tunnel will be excavated through 4 access tunnels. Three different access adits are conceived on the French side: Saint-Martin La Porte, La Praz and Modane, and one on the Italian side: La Maddalena.

The excavation of the base tunnel has started with the 8 km section from Saint-Martin La Porte to La Praz.

Alpina carried out the Supervision of works of the access tunnel in Saint-Martin La Porte (in JV with Egis and Antea) and currently is carrying out the Supervision of works of the first 8 km section of the base tunnel (in JV with Egis).

The Cityringen is an expansion of the Copenhagen Metro; the opening of the line is scheduled to July 2019. The 15,5 km City Circle Line will serve 17 stations.

Alpina carried out the detailed design of the structural works of two stations (Kobenhaven H and Enghave Plads).

København H is a deep station 22,6m wide and 64,4m long, located in Stampesgade on the western side of the existing train station. The excavation depth of the station is approximately 24 m below existing ground level. The station has a 9m wide platform, and is provided with skylights. The new station provides an underground connection, at concourse level, to the existing platform tunnel of København H railway station. The station box is built using top down construction methods in order to control the ground water and to limit the impact on existing buildings and structures from settlement to an acceptable level. Retaining structures consist of secant piles with a diameter of 1000 mm, for depths up to 28,0 m.

The Enghave Plads  station is a semi-shallow station, located at Enghave Plads. The station has a 7m wide platform, and is provided with skylights. The dimension of the station are 20,6m wide and 64,4m long. The concourse level and technical level are merged, and the space for technical facilities is provided in a shallow underground extensions at concourse level along the southern side and at the eastern end of the station. Retaining structures consist of secant piles with a diameter of 1000 mm, for depths up to 23,50 m.

The planned route of the new Metro line of Istanbul runs for about 12 km, starting from İstinye port and ending in Kağithane with a total of 10 underground stations (İstinye, Siteler, Karayemis, İtü, Maslak, Ayazağa, TT Arena, Şirintepe, Cendere, Kağıthane), notably Alpina has been involved in the design of Karayemis and Itüstations.

The new twin metro line tunnels will be excavated by means of TBM/EPB machines, having an excavation diameter equal to 6,60 m. 

One of the most important station in the new Metro Line is İTÜ station; it is located in a quite barycentric position of the whole alignment and it will allow the link with the existing M2 line in Maslak, one of the largest financial district in Istanbul. The station will service also the Istanbul Technical University.

The relevant size of the underground excavation, its depth and width associated with some criticalities of the rock mass interested by the excavation, imposed the choice of a quite complex multi-staged construction system to overcome the aforesaid complexities.

The S.S. n. 1 Aurelia bis in Arma di Taggia Ospitaletti – Road bypass extends between the municipalities of Arma di Taggia and Sanremo. The road has a total length of about 9,2 km and runs entirely on a new route along the hillsides that stretches for almost 80% of its length in tunnels. There are 6 junctions, 7 tunnels of which 5 two-bore of which 2 artificial and 2 single-bore, for an overall total of 7 km and two viaducts.