ABOUT

GEG carried out the detailed design for improvement and reinforcement of the railway tunnels of Caíde, Campainha, and Gaviara located on the Douro Railway line. This project was carried out in order to improve the tunnels’ safety and structural conditions and to allow future electrification of the railways.

These centenary tunnels built between 1876 and 1878, in single ballasted track (Iberian gauge) have a total extension of 1.571 for the Douro’s railway tunnels.  In 2019 Douro railway, between Caide-Marco de Canaveses is reopened to operation, and the rail trip between Porto and Marco, in Douro, has now a duration of one hour and 15 minutes.

• Caíde’s Tunnel

This tunnel is 1086 meters long and serves Douro’s railway, which is in single ballasted track. The tunnel crosses a geological formation of granites, being supported by a granite masonry lining. In the inspection of the tunnel were detected pathologies typical of this type of tunnels, such as water seepage, voids in the masonry contour and mortar degradation in the masonry joints. In zones less weathered punctual solutions were applied while for zones more damaged continuous solutions, such as shotcrete, were prescribed.

• Campainha’s tunnel

Some of the solutions to improve the safety inside and outside the tunnel included rehabilitating and improving the lining, foreseeing new niches, lowering the invert and track in order to allow the future electrification of the railroad, improving the portal slopes and implementing a complete new drainage system, not only to drain the lining but also the track, longitudinally. The tunnel was constructed before 1878 and has a length of 227 m.

• Gaviara’s tunnel

The tunnel was constructed before 1878 and has a length of 227 m.

Rehabilitation design

The scope of work developed by GEG comprised a detailed inspection plan in order to diagnose the structural and drainage problems and the rehabilitation design itself which was applied not only to the masonry lining but also to the portal slopes, the new niches, the lowering of the track, the lining and track drainage systems, Health and safety plan, design of a new portal, among others.

The design included the completion of written documents and drawings in order to provide the proper interpretation of the solutions and measures to be implemented as well as a detailed description and illustration of the construction stages and methodologies, particularly for the lowering of the track, for the shotcrete works and for the demolition, temporary support and construction of niches and service chambers.

The rehabilitation works elapsed without a complete suspension of traffic, but railway traffic was affected by a speed limitation in this zone. Works took place during night periods, whose duration was longer during the weekend.

The works were entirely carried out by GEG (Prime Contractor whose share was 100%) between 2003 and 2009 and fulfilled the works duly and promptly according to the schedule and scope of work which had been planned and agreed by the Portuguese Railways Authorities.