The Pajares tunnel is a railway tunnel that is part of the Pajares variant, a new railway access to Asturias from the Central Plateau that replaces the Pajares ramp. It is made up of two parallel tubes, one for each direction of traffic, 24.6 km long. It is the second longest built in Spain, the sixth longest in Europe and the seventh in the world as of 2009.
The works began in July 2005, and were scheduled to be completed in 2012, but large water leaks caused delays, cost overruns and environmental impacts. Reliability tests began at the end of February 2023,[1] and it was inaugurated on November 29, 2023. The King of Spain, Felipe VI; the president of the government of Spain, Pedro Sánchez; the president of the government of Asturias, Adrián Barbón; and the Minister of Transport "Ministerio de Transportes (Spain)"), Óscar Puente, made the inaugural trip on a Renfe series 130 train from Madrid; the president of the Junta de Castilla y León, Alfonso Fernández Mañueco, joined in León, the only stop on the journey.
It is the second largest civil engineering work that has been carried out in Spain behind the Guadarrama high-speed railway tunnel. More than 4,000 people have worked simultaneously in its construction.
Basic data
Route
This infrastructure crosses the Cantabrian mountain range starting from the municipality of Pola de Gordón (León "León (province)") to the district of Telledo (Asturias).
This large tunnel is part of the Pajares Bypass, a section of the León-Asturias high-speed railway line, which connects the northern subplateau with Pola de Lena, Asturias, crossing the Cantabrian mountain range. Initially the line would be extended to Gijón, passing through Oviedo. This route was finally discarded, with the high-speed trains (Renfe AVE) arriving at the Pola de Lena station, at the end of the variant, where they will make a change of gauge to continue on the conventional network to Gijón.[2][3][4].
Execution process
Its execution began using five tunnel boring machines (four for the large tubes and the fifth for the gallery from Buiza) between July and September 2005 on the Leonese side and between April and July 2006 on the Asturian side.
Tunnel waterproofing
Introduction
The Pajares tunnel is a railway tunnel that is part of the Pajares variant, a new railway access to Asturias from the Central Plateau that replaces the Pajares ramp. It is made up of two parallel tubes, one for each direction of traffic, 24.6 km long. It is the second longest built in Spain, the sixth longest in Europe and the seventh in the world as of 2009.
The works began in July 2005, and were scheduled to be completed in 2012, but large water leaks caused delays, cost overruns and environmental impacts. Reliability tests began at the end of February 2023,[1] and it was inaugurated on November 29, 2023. The King of Spain, Felipe VI; the president of the government of Spain, Pedro Sánchez; the president of the government of Asturias, Adrián Barbón; and the Minister of Transport "Ministerio de Transportes (Spain)"), Óscar Puente, made the inaugural trip on a Renfe series 130 train from Madrid; the president of the Junta de Castilla y León, Alfonso Fernández Mañueco, joined in León, the only stop on the journey.
It is the second largest civil engineering work that has been carried out in Spain behind the Guadarrama high-speed railway tunnel. More than 4,000 people have worked simultaneously in its construction.
Basic data
Route
This infrastructure crosses the Cantabrian mountain range starting from the municipality of Pola de Gordón (León "León (province)") to the district of Telledo (Asturias).
This large tunnel is part of the Pajares Bypass, a section of the León-Asturias high-speed railway line, which connects the northern subplateau with Pola de Lena, Asturias, crossing the Cantabrian mountain range. Initially the line would be extended to Gijón, passing through Oviedo. This route was finally discarded, with the high-speed trains (Renfe AVE) arriving at the Pola de Lena station, at the end of the variant, where they will make a change of gauge to continue on the conventional network to Gijón.[2][3][4].
Execution process
The tunnel boring machines extracted 4.3 million m³ from the tunnels. Each one is 24.6 kilometers long, with a diameter of 8.5 meters and a separation between the two of 50 meters. It has emergency galleries joining both corridors every 400 meters, a large autonomous room located halfway along the route with space for 1,200 people for use in an emergency, and an installation of reversible fans that can inject air if a fire occurs. The design has been made so that the trains that travel through it can reach high speeds without compromising the infrastructure.
Its execution has revealed notable shortcomings in foresight, which have increased the cost of the tunnels from 1.8 billion euros to almost 4 billion.[5] Critical voices have stated that while the previous studies of the new St. Gotthard tunnel in Switzerland lasted about ten years, in this case they were carried out in a few months.[6] Among these problems, the most serious is the negligent geological studies since the tunnel crosses 20 aquifers, which has caused the condition. of springs in the Cantabrian mountain range and water seepage into the tunnel, which acts as a channel for water from the Leonese side to the Asturian side. The 2003 informative study already anticipated a transfer of 1,144 l/s. However, after carrying out numerous specific actions to waterproof the walls, the total flow (water from both the Leonese part of the tunnel and the Asturian part) collected at the exit of the tunnel has been reduced to about 280 l/s in December 2023. This transfer is estimated at 8.8 cubic hectometers per year.
In 2019 it was decided that one of the tunnels would have an Iberian gauge track, leaving only the other for high-speed rail use.[7] Track I, east tunnel, is of mixed gauge or “three wires” and allows the passage of trains in Iberian and standard gauge for high speed. Meanwhile, track II, west tunnel, is of conventional gauge on a multipurpose sleeper, which allows it to be converted to standard gauge in the future. In addition, it has a changer in Campomanes so that trains can combine the different track gauges and two Train Overtaking and Parking Posts (PAET) in Campomanes and La Robla, with two section tracks each.[8].
The Ministry of Public Works completed the bulk of the works on the Pajares Bypass in 2021. In February 2023, the works were definitively completed and it entered a testing period.[9] After 19 years of construction and nearly 4,000 million euros of investment, it was opened to passenger traffic in November 2023.[10][5].
Basic tunnel data
• - 2 single track tunnels.
• - Length: 24,648 km.
• - Continuous longitudinal slope of 16.8 thousandths, descending towards Asturias.
• - Circular section: 8.5 m in diameter.
• - Section area: 56.75 m².
• - Connection galleries: every 400 m.
• - Distance between the axes of both roads: 50 meters inside the massif.
Its execution began using five tunnel boring machines (four for the large tubes and the fifth for the gallery from Buiza) between July and September 2005 on the Leonese side and between April and July 2006 on the Asturian side.
The tunnel boring machines extracted 4.3 million m³ from the tunnels. Each one is 24.6 kilometers long, with a diameter of 8.5 meters and a separation between the two of 50 meters. It has emergency galleries joining both corridors every 400 meters, a large autonomous room located halfway along the route with space for 1,200 people for use in an emergency, and an installation of reversible fans that can inject air if a fire occurs. The design has been made so that the trains that travel through it can reach high speeds without compromising the infrastructure.
Its execution has revealed notable shortcomings in foresight, which have increased the cost of the tunnels from 1.8 billion euros to almost 4 billion.[5] Critical voices have stated that while the previous studies of the new St. Gotthard tunnel in Switzerland lasted about ten years, in this case they were carried out in a few months.[6] Among these problems, the most serious is the negligent geological studies since the tunnel crosses 20 aquifers, which has caused the condition. of springs in the Cantabrian mountain range and water seepage into the tunnel, which acts as a channel for water from the Leonese side to the Asturian side. The 2003 informative study already anticipated a transfer of 1,144 l/s. However, after carrying out numerous specific actions to waterproof the walls, the total flow (water from both the Leonese part of the tunnel and the Asturian part) collected at the exit of the tunnel has been reduced to about 280 l/s in December 2023. This transfer is estimated at 8.8 cubic hectometers per year.
In 2019 it was decided that one of the tunnels would have an Iberian gauge track, leaving only the other for high-speed rail use.[7] Track I, east tunnel, is of mixed gauge or “three wires” and allows the passage of trains in Iberian and standard gauge for high speed. Meanwhile, track II, west tunnel, is of conventional gauge on a multipurpose sleeper, which allows it to be converted to standard gauge in the future. In addition, it has a changer in Campomanes so that trains can combine the different track gauges and two Train Overtaking and Parking Posts (PAET) in Campomanes and La Robla, with two section tracks each.[8].
The Ministry of Public Works completed the bulk of the works on the Pajares Bypass in 2021. In February 2023, the works were definitively completed and it entered a testing period.[9] After 19 years of construction and nearly 4,000 million euros of investment, it was opened to passenger traffic in November 2023.[10][5].
Basic tunnel data
• - 2 single track tunnels.
• - Length: 24,648 km.
• - Continuous longitudinal slope of 16.8 thousandths, descending towards Asturias.
• - Circular section: 8.5 m in diameter.
• - Section area: 56.75 m².
• - Connection galleries: every 400 m.
• - Distance between the axes of both roads: 50 meters inside the massif.