Tunnel and bridges under the Lisbon sky
Transforming private traffic into travel on public transport. This is what cities of all sizes are trying to do to reduce the impact of pollution and improve the quality of life by reducing travel time. Even in Lisbon, the capital of Portugal, a project to extend the metro network is underway with the aim of removing 3,700 vehicles a day from the roads and reducing atmospheric emissions by 6200 tonnes of CO2 each year.
The engineering firm responsible for the preliminary project is led by a structural designer who trained at ETH Zurich and who has a passion for designing amazing viaducts and other fascinating infrastructures in his blood: Luis Câncio Martins. We interviewed him.
What projects have you done that you consider most important?
Every project has its own specificity and is thus unique. Accordingly, every project is the most important at a time. I would nevertheless highlight the IC8 highway bridge over the Zêzere river in Portugal.
Why do you consider them most important? What characteristics did they have?
The Zêzere Bridge was the first major structure designed by myself. Ranked as the highest bridge in Portugal at the time when it was finished (1994), it has a 180 m long main span and up to 100 high piers. It was executed by the free cantilever method.
Is Portugal investing heavily in infrastructure? Is it possible to combine development with sustainability?
Public investment in infrastructure in Portugal is dictated by political and economic cycles. Under the current Recovery and Resilience Plan funded by the EU, significant investments are being channeled to public infrastructure, in particular railway, within a limited time frame.
Shifting to public transportation to the detriment of private transportation is mainly motivated by sustainability considerations.
What are today the main criticalities and opportunities for those involved in civil engineering in Portugal?
The main difficulty are the fluctuations of public investments and, as a consequence, the uneven flow of work. Short-term opportunities are associated with the strong demand in railway infrastructure.
About the Lisbon metro what is the role played by your engineering firm?
LCM is responsible for the Preliminary Design of the Extension of the Red Line (Amoreiras-Campo de Ourique-Infante Santo-Alcântara).
What aspects will you deal with?
We are responsible for coordinating all architectural and engineering design work produced by the design team, a blend of Portuguese, Brazilian and Swiss companies, as well as for the design of the structural works.
At what point is the design process?
We have submitted a pre-design that is being used for the environmental impact assessment and are now working towards the submittal of the Preliminary Design, based on which the Client (Metro Lisboa) will launch a design-build tender.
What are the solutions identified and what are the technical difficulties overcome?
The major challenge are the extremely short deadlines for designing and building the new metro line, due to be in operation in 2026. Technical challenges both in relation to the design and execution of the works include the interferences with the in part dense urban environment and built heritage, as well as the crossing of the Alcântara Valley by means of a viaduct.
The Metropolitano de Lisboa (ML) wants to extend the Red Line between São Sebastião and Alcântara stations. The extension of the Red Line between São Sebastião and Alcântara should start from the already built area, located after São Sebastião station, through a section of tunnel built next to the Palace of Justice and will have a total length of about 4 km with 380 metres on the viaduct. Three new metro stations (Amoreiras, Campo de Ourique and Infante Santo) and a surface station (Alcântara) are planned to be built along the double-track tunnel.
In the process of developing and evaluating the solutions in the preliminary study phase, Metropolitano de Lisboa promoted meetings to present the route solutions with various authorities and bodies.
The extension of the Red Line is part of the Recovery and Resilience Plan 2021-2026, with a total funding of 304 million euros. The expectation is that this Red Line extension will be put out to tender in 2022 and become a reality in 2025/2026.
In the first year of operation, traffic is expected to increase by 11 million passengers (4.7%) on the entire metro network. According to studies, the new configuration of the Red Line will remove 3700 individual vehicles from Lisbon’s daily traffic, which means 6200 tonnes less of CO2 in the first year of operation.
Luis Câncio Martins
Year of birth: 1965
Professione: Structural designer
After graduating and obtaining a PhD in civil engineering from ETH Zurich, he worked in structural engineering, working in Lisbon for Teixeira Duarte SA and in Zurich and Paris for Calatrava Valls SA. He currently works for J L Câncio Martins Structural Engineers in Lisbon, where he is managing director. The company, founded in 1963 by Professor José Luis Câncio Martins, has established itself over the years in the design of complex structures for transport systems, buildings, maritime works and industrial structures.