Threaded into the urban fabric of the City of London, Liverpool Street Elizabeth line station provided unique challenges to the teams working on its construction.
Work was running six months behind schedule due to tunnelling delays, but the Laing O’Rourke team were able to recover this time using offsite solutions and a design for manufacture and assembly (DfMA) approach.
This enabled 17 months’ programme activity to be completed in 11 months.
Laing O’Rourke operations director Steve Jones explained: “We were looking to recover programme time and have fewer men below ground.
“If one station doesn’t allow the railway to be built that’s a critical delay.”
The grooved and angled ceilings in both ticket halls were formed from pre-cast panels, manufactured at Laing O’Rourke’s Centre of Excellence for Modern Construction (CEMC) in Nottinghamshire. Instead of a flat ceiling, these create a greater sense of space and movement and resemble the pinstripes often seen in the suits of City workers.
Pre-cast concrete platforms were also made at the CEMC and then assembled on site. Glass reinforced concrete (GRC) is the “dominant finish” in the platform and concourse areas, Jones said, while the ticket halls are predominately glass, stainless steel and vitreous enamel finishes.
The platforms feature “sweeping curves” to “create greater site lines”.
“The architect had the vision,” Jones added. “And the technical team made a detailed model.”
Meanwhile, the Moorgate mechanical and electrical risers to the shaft were manufactured at Laing O’Rourke’s specialist off site facility at Oldbury, West Midlands.
In addition to this, the platform edge screens were also an offsite component supply from specialist suppliers and benefited from prototyping trials and using pre-assembly techniques.
It’s an approach that worked effectively to recover time in what has proved to be a complex construction location.
At 34m below ground at platform level, Liverpool Street is the deepest of the new central London stations and has a total of 15 escalators and seven lifts.
A maze of sewers, existing Tube lines and the Post Office Railway had to be navigated for the station, while nearly 4,000 skeletons from the Bedlam burial site and thousands of artefacts dating back to Roman times were also discovered.
The construction team did “an amazing job”, according to London Underground managing director Andy Lord (see video below). https://www.youtube.com/embed/HaASyUM6CVA
As part of the work undertaken by Crossrail, a refurbished station entrance for Moorgate station on Moorfields also opened last week to customers using the Circle, Metropolitan and Hammersmith & City lines.
The rest of the new station will open with the start of cross-London Elizabeth line services in the first half of 2022.
Stretching from Moorgate in the west to Broadgate in the east, the Elizabeth line ticket halls are connected by two mined platforms. Fully accessible ticket halls provide direct interchange with the Northern, Central, Metropolitan, Circle and Hammersmith & City lines, as well as National Rail services to Stansted and Southend airports.
When the line opens, the station will have a central concourse linking Liverpool Street and Moorgate stations as well as two platforms that are more than 200m long.
Department of Civil Engineering https://www.ibu.edu.ba/department-of-civil-engineering/