Francisco Bernardo
COBA Consulting Engineers SA
geotechnical engineer
Event organised by The British Tunnelling Society
The Green and Yellow line extension is the most significant upgrade to Lisbon’s rail underground network in the last decade. By creating a new connection between the two existing lines, this project will enable forming a circle line which will enhance the usability of public transportation services in the city centre.
The project comprises a total of 1984 meters of running tunnels, two new underground stations, upgrades at Rato and Cais do Sodré stations and a new flyover at Campo Grande. Running tunnels and station platform tunnels will be excavated using the NATM/SCL construction methodology. The project includes many technical challenges, such as running tunnels gradients of up to 4%, and variable geological and hydrogeological conditions.
Tunnelling has already begun in April this year for Construction Package 1 and enabling works for Construction package 2 started in June. Services are planned to start in Q4 2024.
In this presentation, Francisco will provide an overview of the extension works, the associated challenges and proposed solutions.