Investigating the rehabilitation methods of Victorian masonry tunnels in the UK

Abstract

The Victorian tunnels that lie on the nation’s railway network have been vital to facilitating a reliable rail service across the country for the past 150 years. However, some of these tunnels have started to challenge the existing network. These tunnels were originally constructed using several rings of brick masonry as a lining. After many years, these brick linings have started to degrade and bricks are becoming dislocated from their surrounding rings, falling on the tracks. These tunnels are also of an outdated gauge, this is slowing Networks Rails plans to modernize the rail network. Network Rail plans to electrify the rail network and increase the speed and size of trains, and these tunnels are considered a hindrance. Network Rail is looking for potential economically viable repeatable methods for resizing and relining these tunnels. An initial investigation into this problem is performed by examining case studies of tunnels that have been resized and relined worldwide, what was learned from this has subsequently been synthesized into a tunnel refurbishment method matrix. This problem is further examined in detail by modelling the enlargement of Whiteball Tunnel, mimicking the use of a Tunnel Enlargement Machine to analyzing the feasibility of this method. This preliminary modelling indicates that utilizing this innovative technology would be feasible if the appropriate support is put in place.