Soil nailing and sheet steel piling will form a key element of a railway tunnel upgrade that is about to start in Lancashire to enable line electrification to be completed.
Network Rail has said that the line between Chorley and Leyland, through Chorley Tunnel, will be closed from this Saturday for the “significant” engineering works, which are expect to take six weeks.
Main contractor Murphy Group will lower the level of the trackbed throughout the 113m tunnel to accommodate overhead line equipment. The approach cutting to the tunnel will be strengthened ahead of track bed lowering work through use of sheet piling and soil nailing. Within the tunnel itself the existing ballast will be replaced with a cast insitu concrete track slab to lower the level of the rails sufficiently to accommodate the overhead electricfication equipment.
Network Rail area director Ian Joslin said: “More than £1bn of investment is being made to provide a better railway and boost the economy across the north of England.
Outside of the portals, to the north, the original 16 flying arches, designed to strengthen the retaining walls, will replace temporary props at a higher level to accommodate the overhead line equipment.