When one door closes, another one opens”, so telephone inventor Alexander Graham Bell said of life, and so it has happened for the Spanish tunnelling industry, which was strongly affected by the financial crisis in 2008.

The recession helped the infrastructure companies to become more efficient and to take on an international perspective.

Avelino Acero, vice-president of Spanish Association of Tunnels and Underground Works (AETOS) explains that Spanish companies currently have 80 per cent of their activity abroad while only 20 per cent is in their home country. “The domestic market mainly involves rail tunnels, but [the market is very slow moving],” Acero says. “Unfortunately the amounts devoted to infrastructure investment are much smaller than in the past, and this has not recovered yet, although the economy has showed some signs of recovery.

“The Spanish tunnelling market has made a big effort to strengthen its skills to operate abroad. We have a lot of activity in Latin America with metros and hydropower works; we also have a very good presence in Britain with rail and metros; we have won many projects in the USA and the Middle East. We have shown in many cities around the world that we are able to grow.”

Ricardo Cortés, technical director for Association of Infrastructure Contractor and Concessionaires (Seopan) explains that in many cases, Spanish infrastructure groups began to become active internationally in the 1970s. This was the result of mergers with and acquisitions of other companies, both Spanish and foreign, which have contributed to the increase of its international construction activity.

“Nowadays, the largest infrastructure companies represent an annual production volume of EUR 80bn (USD 90bn) collectively, providing employment to more than 450,000 people,” says Cortés. “International activity currently represents 76 per cent of total turnover and 90 per cent of construction activity.

“Tunnel construction is one of their main activities and they have taken full advantage of the vast experience acquired in the works realized in Spain and throughout the world. Examples of these projects have been the construction of the: Alaskan Way Tunnel in Seattle (USA), in which the TBM used had the largest diameter of 17.48m, New York Metro, Panama Tunnel, Follo Line railway Tunnels (Norway), Thames Tideway Service Tunnel (London), among many others.”

Jesús Javier Mateos Hernández Briz FCC technical services director says that FCC has been able to adapt itself to the international crisis thanks to a “capacity to develop the engineering and construction of multiple projects, thus being a benchmark in the execution of civil works (roads, railways, airports, hydraulic works, maritime, tunnels, bridges, metros, purification stations) and building (residential and non-residential: hospitals, football stadiums, museums, offices)”.

Meanwhile, Antonio Muñoz, Acciona director for railways and tunnels explains that the internationalisation of Acciona had begun many decades before, but the 2008 crisis accelerated the process.

“Public and private infrastructure projects in Spain dried up, driving some of the smaller, more regional construction groups into bankruptcy,” says Muñoz.

“The large groups survived because they already had a foothold abroad, a place from which to expand.

“This tendency encouraged us to focus in the development of new projects at a global level and somehow the financial crisis is one of the reasons why Acciona is nowadays considered as a global reference in the international infrastructure sector.

“Perhaps one of the positive side effects of the financial crisis is that it forced us to become far more efficient in our use of capital, in our construction methods and in our bids. It was the only way to succeed in a fiercely competitive international market.”

Muñoz adds that 76 per cent of their construction order book and a similar proportion of their EPC industrial installations for private clients are international contracts with a broad and balanced geographical spread.

Native Technical Challenges

Spain is varied geologically and topographically. During the construction of the rail and road networks, Spanish constructors have had to face different challenges, solving them using different excavation methods and specific equipment in each case.

In terms of construction methodology, Briz says the New Austrian Tunnelling Method and TBMs have been employed the most, representing 36 per cent and 56 per cent of the total of the constructed tunnels respectively. The rest 8 per cent were built with some specialised methodologies such as pipe jacking or the Bernold Method (see terminology box opposite).

“With regards to the use of TBMs, some 232km of tunnel have been built using soft ground TBMs equipped with face pressure control systems, which provides an idea of the significant demand for urban tunnels, including metro and intercity rail connections, versus 160km of tunnels built without a pressurised face, usually for high speed rail networks.” In Briz’s opinion, one of the main challenges of the tunnelling industry in Spain is the dependence on international equipment manufacturers for both main and ancillary equipment for underground works.

“The lack of any national manufacturers of TBMs, drilling equipment or road headers, forces us to rely (at different degrees depending on the type of equipment) on international manufacturers, usually in markets that have a relatively low level of competition. This can lead to delays on project schedule and affect the project budget.”

On the other hand, Briz says that the economic crisis had an impact on the national industrial fabric, including companies focused in the production of ancillary equipment and accessories for tunnelling. This had two effects: slowing down the technical development of products and, in the worst scenario, the partial or complete closure of manufacturers and the loss of know-how.

Types of Infrastructure

Briz explains that FCC has a long experience in tunnel construction, which started in 1949 with the Barcelona Metro extension.

“Since then, and with 60 years involved in tunnelling, FCC has successfully constructed around 600km of tunnel, through different geologies and using many different tunnelling methodologies,” Briz says. “To appreciate the experience gathered over the years, we have to consider the first the type of infrastructure built, and then the construction methodology employed.

“Regarding the type of infrastructure, 30 per cent of the tunnels were for the road network with a length of almost 178km; 61 per cent were for railway infrastructure, including railway network, underground and high speed train projects, adding up to 366km. The remaining 53km of tunnels were for hydraulic projects. Those figures reveal the importance of the rail infrastructure, especially in a high demand of urban subways facilities, to solve the surface traffic issues in the big cities, and the High Speed Train railways, whose alignment’s strict specification fulfilment often require the construction of tunnels and viaducts to the reach.”

Meanwhile, Muñoz says that Acciona has constructed more than 600km of tunnels in a range of ground conditions. “Acciona is building metros in Dubai and Quito; we are boring the longest high-speed railway tunnel in Scandinavia; the Chuquicamata and Andina Minning projects in Chile; we are building one of the largest hydroelectric dams in Canada, as well as the world’s largest photovoltaic plant in the United Arab Emirates or some of the largest reverse osmosis plants in the Middle East,” Muñoz says. “Such achievement has only been possible thanks to the use of reference projects and the knowledge acquired in the Spanish market.

Projects

Amongst the main FCC projects, Briz highlights the 28km Túneles de Guadarrama, (for the High Speed Rail Network in north and northwest Spain), which is the longest rail tunnel in Spain, sixth in Europe and in the top 10 in the world. FCC Construction, as a member of the group responsible for the construction of the ‘north entrance’ section, was involved with the excavation of more than 28.8km of tunnel using two double shield TBMs. The tunnel formations are orthogenesis, meta-sediments and plutonic granites, separated by brittle fault systems. The maximum overburden is 992m.

Two TBMs were used: one Wirth-NFM with an excavation diameter of 9.45m and one Herrenknecht with an excavation diameter of 9.56m. The inner diameter of the precast segments is 8.5m, the length is 1.6m and the thickness is 320mm. The tunnel was excavated from 2002 to 2005.

As for NATM, the Bracons tunnel stands out for Briz with its 4.32km of length and a maximum excavation area of 114m2. The tunnel goes through a formation of marl and sandstone. The excavation period was from 2003 to 2005,” Briz says.

The Barcelona Metro is also worth mentioning, because of its difficult geology. Constructed using both EPB and rock shield TBM, manufactured by a JV of Mitsubishi Heavy Industries and Duro Felguera, the 11.95m diameter machines went through sand and silt ground under the water table or granite stretches. Two different cutting heads had to be used to complete the full length of the tunnel.

“Also of note is the underground drive of the M-30 bypass tunnel in Madrid is 4,200m long and 3.652m have been excavated with a 15.01m diameter EPB, the larger in diameter EPB used until then.

“The excavation time was from April to October 2006. The typical geotechnical units include fills, alluvia, Miga sand, clayey sands, toscos and “peñuelas” (overconsolidated clays). The inner diameter of the precast universal ring is 13.45m with a thickness of 600mm and a length of 2m.”

Nowadays and with a highly developed railway network, the main tunnelling works undertook by FCC in Spain are for road infrastructure, such as the Vallirana Tunnels, where a heavy road header machine was used and which is now in the final lining works. In the same stage are the tunnels of Arguis, where the lining is being made using a crawler-driven formwork. The excavation method used is the NATM.

Briz explains that these works represent approximately more than 30 per cent of the high-speed lines of the country. “It is worth remembering at this time, that Spain is the leading European country in terms of length of high-speed network and the fourth in the world, behind China,” says Briz.

“We designed and built some of the main metros in the world such as Riyadh, Doha, Panama, Peru, which are examples of more than 326km of metro built.

“Regarding airport infrastructure we add more than 4.5million sqm of airstrips and take-off, more than 2.3million sqm of air terminals, used daily by thousands of passengers around the world. We transport energy through the 3,000km of gas pipelines and pipelines developed. We also executed hydraulic and water works, with more than 48 executed dams, some 76km of docks and more than 10,500km of pipeline for water transport.”

Among the major Spanish tunnelling projects executed by Acciona over last 20 years, Muñoz picks out the following for a special mention:

  • Somport International Tunnel. The tunnel has a length of 8.5km and it was excavated by drill and blast. This tunnel, which links Spain and France, was completed in 2002 and is still the longest road tunnel in Spain. After the lining, the tunnel has a free section of 66sqm.
  • Metronorte Lot 1B, 1C, 2A. The project was divided into two adjacent lots that were executed simultaneously, including 10km of metro line, (bored with two EPB TBMs) and six stations in total. The tunnel has a 9.4m diameter and was excavated through sand and clay soil.
  • Guadarrama Tunnels. The contract awarded to Acciona included the first 15km of the left tunnel and 13km from the right tunnel.
  • Pajares Tunnel Lot 1. TBM construction of two parallel tunnels measuring 24.6km in length each, Acciona executed the excavation of 25.9km and a 2,045m long tunnel bored by drill and blast. The tunnel has a 9.9m in diameter and was excavated through slates and limestone.
  • Vigo Das Maceiras. The tunnel is two twin single-track bores, 8.2km long each. It is bored using two 9.51m-diameter double-shield TBMs (one for each tube). The rock excavated was very hard and abrasive.

Future Expectations

According to Muñoz the future of the Spanish infrastructure sector seems promising, projects such as extending the highspeed rail network, modernising water treatment networks and keeping the infrastructure, are relevant initiatives that encourage Acciona to innovate and to develop new procedures for the Spanish market.

“We also see infrastructure groups becoming increasingly involved in the operation and maintenance of infrastructure and in helping design P3 schemes for public works that would not otherwise be financed or built,” Muñoz says.

“Acciona is currently participating in a few bidding processes and we have already been awarded with some new development projects. Therefore, we can anticipate that in a couple of years we will see the industry fully operational.”

Muñoz believes that the Spanish tunnelling market will need large investments in infrastructure in the near future to continue developing the HSR network with projects like the Basque Y city bypasses, the Extremadura HSR Extension or the Madrid – Basque Y connection.

Likewise Spain has several large urban centers, which shortly will need to continue their development.

Cortés from Seopan doesn’t share this optimistic perspective regarding the future: “There are no on-going large tunnel projects and so there is no current activity and the prospects for the future are bleak.

“At this time, there is so much less activity than in the past. Tunnel construction in Spain has essentially come to a complete halt. The only projects that are being developed are those that started a few years ago, however, this depends on public budget funding such as the high-speed train tunnels to Galicia or the tunnels of the ‘Basque Y’. At the moment there aren’t any new tenders and important projects related with tunnels being awarded.

“There are no prospects particularly for this area, despite the fact that there are priority works to be undertaken in terms of tunnels in Spain.

“To solve this situation, the government should promote the concession model in order to finance the necessary works in our country.”

Political Impasse

In Spain the main investment is for the high-speed rail. “Until now we have completed the east and north-east, most of the south-east and west and we are working on the north west,” says Fernandez-Bollo, Aetos vice president. “There are also few works for slow railway tunnels, but they are just for maintenance.

“There are some highway tunnels but they are very small. The last important work was a highway that goes from the French Frontier to the Portuguese borders going along the Mediterranean.”

Fernandez-Bollo adds: “If we compare with two years ago, I would say there is more work but the increase is very little.” Acero adds they don’t have any astonishing expectations now, but they can really expect that as they go near the completion of the high-speed railway net, “politicians need to understand to invest more in infrastructure to boost the economy.”

“One of the most important recent projects is the Basque Y [to be featured in an upcoming issue of Tunnels and Tunnelling – Editor] because we are connecting the Basque country, which had an inefficient railway net,” Acero says. “This will be a relevant project to connect Madrid to the French border in only two hours.

“We are connecting the whole Mediterranean area thanks to the high-speed railway network.”