Crossrail is delivering a new railway which will be known as the Elizabeth line when it opens through central London from 2018. The finished railway will be an accessible route of 40 stations from Reading and Heathrow in the west, through central London and to Shenfield and Abbey Wood in the east. Where the railway passes beneath central London it comprises 21km twin-bore tunnels together with 8 new sub-surface stations, two above ground stations, 3 large crossover caverns and 5 portals.
GCG has been engaged since the 1990s as the Specialist Geotechnical Advisor to Crossrail Ltd. Our role has covered all geotechnical aspects through the various phases of the project, from scheme development, through the Parliamentary approval process to detailed design, and construction.
Our role on the project was wide ranging. It included feasibility and option studies; ground movement and building damage assessments; ground movement mitigation studies; specifying and supervising ground investigations and monitoring of construction work. GCG also created and managed centralised databases containing all the geotechnical ground investigation data and the groundwater monitoring data.
Members of GCG also sat on an expert panel which advised Crossrail on the design and construction of the project as a whole. Our staff were also seconded into the Crossrail client organisation where they took on a Technical Authority role for the geotechnical aspects of the design and construction across the eastern half of the alignment. This involved a close involvement in the temporary works and construction arrangements for the riskier and more unusual elements of the project
GCG were also closely involved in some contractual aspects of the project, notably the development and production of a novel and successful format for Geotechnical Baseline Reports. These were incorporated in all the construction projects with a significant below ground scope.