Construct lift shaft and escalator interface
Year - 2016
Client – BBMV/CROSSRAIL
Contact – Tony Goble (BBMV)
Overall Cost – £4,500,000
As part of the larger Crossrail project, the main contractor had a need for interface works between the existing station and 2 proposed new breakthroughs from the tunnelling works being undertaken to form 2 new pedestrian access routes to the Northern Line at Moorgate station. AP6 was to be a new escalator access and AP10 was to be a new Lift access. Both openings would require a complex reinforced frame to the cross passages that would need to be excavated in small bays, poured with a early high strength concrete and allowed to cure before the adjacent bay could be broken out. Works were at all times sequenced to support the existing cross passage brick arch to prevent a catastrophic collapse.
Both cross passages were worked on simultaneously in order to meet the projected finish date for tunnelling works and the scheme was developed all the way through to account for obstructions and ground conditions.
Works included station finishes around the two opening sets in the form of manholes, drawpits, Wall tiling and floor finishes.
Specialist concrete products were used that all Spoortech operatives are trained to mix and place, ongoing batch quality was undertaken by weighing samples on site to ensure the correct density and on site testing facilities were set up to crush cube samples and ensure that the 40N strength was achieved within 24 hours to allow the next bay to be broken out.
Works were inspected and signed of by all stakeholder representatives at every stage before the could progress, this ensured that the quality control and traceability was always maintained.
We had an early involvement in this project and supplied construction and design and constructabilty input from tender stage as we had experience from a similar scheme at Kings Cross and had worked closely with the client team to deliver similar projects in the past.
Our client understand from the initial tender that they did not have the resource or experience of working in a London Underground environment and would require a specialist interface contractor to undertake the works that had all the required training and in house resource to work on L.U. This would enable the client to concentrate on the serious business of delivering the labyrinth of pedestrian tunnels between Moorgate, Liverpool Street and Finsbury Circus as well as two Crossrail tunnels running through the works.
Perfect delivery was achieved and our joint efforts were commended by London Underground and Crossrail and noted that on a project of this size, there were no incidents despite having moved 40 tons of spoil from site during engineering hours and carried in the equivalent in high strength concrete and reinforcing.
No complaints were received over the eight month project although all access to site was through a busy station.