Hooley cutting stabilisation

摘要

Hooley Cutting on the north side of the North Downs just south of Croydon, is on the main London Brighton railway line and over 175 years old. In recent years there have been a number of land slips from the steep cutting sides. Following preparation work over the Christmas period at the end of 2011, Network Rail commissioned the stabilisation to this cutting. An internal collaboration between BAM Nuttall Rail and specialist geotechnical division BAM Ritchies successfully carried out the work, completing it in early 2013. The project was a double winner at the 2013 ICE SE Engineering Excellence Awards as well as winning Project of the Year at the 2014 Ground Engineering Awards. This paper provides a short history of the issues necessitating the stabilisation work, will cover the design development aspects as well as the geotechnical and construction techniques including the management of environmental issues (dealing with the presence of 'Roman Snails' - a protected species). Advanced track protection measures, steep slope soil nailing techniques using rope supported and excavator mounted drilling rigs and the innovative sprayed concrete beam and grillage system, allowed the remedial solution to be completed during normal rail operations, not affecting passenger journeys.