The “Proyecto de Accesos” area corresponds to the structures to be built on both sides of the future Sagrera High Speed Train Station. Those works include two Spanish width railways, corresponding to Vilafranca – Massanet and Vilanova – Mataró lines, and the UIC width railways for the high speed train connecting Madrid to Barcelona and to the French border. The Spanish width railways are part of the Barcelona Metropolitan Railway System and they must be kept in service during all the works. This is one of the technical challenges of the project. Also, it is necessary to allow the high speed trains traffic during some of the works.

The aim of the project is to redistribute the Barcelona Metropolitan Railways and the High Speed Railways. Those railways must be reorganized in plant and elevation before entering and after going out of the station. Because of this, very complex structures are required to allow all the underground crossings at different levels.

There are also two underground boxes, one on the south bound and the other on the north bound, both for cars, taxis and buses which are heading for or leaving the station and connecting it with the city.

When the works will be finished, all the structures will be underground and an almost horizontal surface filled with soil will connect both sides of the railway corridor. This area will be used as a huge park.

Some of the structural elements used in the project are:

– Reinforced concrete diaphragm walls
– Reinforced concrete walls
– Reinforced concrete floors for railways and car traffic
– Composite piers (concrete-steel) and reinforced concrete piers.
– Piles and pile caps – Reinforced concrete railway slabs
– Special structures to bridge existing metro tunnels
– Prestressed, pretensioned and post-tensioned concrete beams
– Wall beams, with long spans and large depths.
– Underground reinforced concrete boxes

The most part of the works is built under the actual soil level. So, diaphragm walls are designed to resist the soil pressure and also are used as a support for the different levels of slabs.

Sometimes, temporary struts or tie backs were needed depending on the construction procedure. Up to 26 different kinds of diaphragm walls have been designed.

There are up to 5 different floors and 8 different slabs supporting the railways. The floors are connected to the diaphragm walls when located under the water level.

Due to the large extension of the roof, most of it is built with precast concrete elements. In situ concrete slabs were designed where the connecting holes were located and where the geometry was irregular.

Due to the large loads and the soil layers all the foundations are formed by piles. Besides, three slabs were designed to bridge the existing metro tunnels. Those slabs are supported by pile walls. It was also necessary to design many special structures due to interferences with utilities, existing bridges, tunnels, sewage, etc.

To summarize, this is an extremely complex huge underground structure built in an urban area that requires a very specialized and detailed design. The Bridge Technologies’ engineers are very proud of being chosen to make possible this engineering challenge.