Interviews

Victoria Station Upgrade

Craig Prangley, project director of the Taylor Woodrow/BAM Nuttall joint venture, and Glenn Keelan, programme manager at London Underground, give an update on the Victoria Station Upgrade project.

Four years into London Underground’s £700m Victoria Station Upgrade project, the Taylor Woodrow/BAM Nuttall joint venture (TWBN) is making significant progress in providing a refurbished extended Underground station with improved and new ticket halls.

As part of the project, a new North ticket hall at the junction of Bressenden Place and Victoria Street with eight new lifts and nine new additional escalators and links to the Victoria Line and District and Circle Lines is expected to significantly increase station capacity and make it step-free.

Craig Prangley, project director of TWBN, which was awarded the contract in 2010, told RTM that over the last few years the key to enabling the work around Victoria has been in solving the logistical challenges.

“The sheer number of people that flow through the Victoria area each morning, which is now approaching 100,000, requires our works to be carefully planned to ensure they can safely reach their final destinations without undue delay and disruption.”

A key measure the JV partners implemented revolved around ‘traffic phasing’ moves that required the team to carry out and complete activities in order to facilitate the next part of the works. In particular, it set up a Strategic Working Group with London Underground and Transport for London to co-ordinate how to develop the scheme while moving traffic around safely. All the project partners have stated how important this collaborative approach has been in facilitating the upgrade.

“Logistics have been a challenge since the day we arrived on site in May 2010, and are still with us today,” said Prangley. “It’s just we understand them now in far more detail and we are able to manage them very closely with our colleagues and the teams that work around the station.”

Glenn Keelan, programme manager at London Underground, stated that as well as tackling the logistical challenges, much wider progress has been made on the upgrade.

“If we look at the slightly larger operation, the progress made on the excavation and the piling in the two main ticket halls has been really encouraging,” he said. “There has been a fair amount of effort put in to overcome the logistical challenges in order to keep the work on track. And now it is really encouraging to see how work is expanding on a week-by-week basis.”

Tunnelling

One area where significant progress has been made is in delivering the new tunnels, which will range from 4.5m-9m in diameter. For instance, works are progressing well on the construction of the Paid Area Link (PAL) 10 escalator tunnel, which is located behind the Victoria Palace Theatre.

The tunnel decline is complete and the JV team is moving onto the construction of the cross-passages that will connect the tunnel to the station, whilst ground treatment works are now commencing beneath the District and Circle Line to enable future phases of tunnelling works.

Works have also commenced on PAL 22, which runs beneath Allington Street and will connect the eastbound District and Circle Line platform to the new North ticket hall.

Prangley said: “PAL 22 is going very well for us, and we’ve had much better rates of progress on that tunnel than we have had previously. That’s to do with the experience and confidence that we’ve gained in the jet grouting process, which has been pretty uniform throughout and allows us to work with a greater degree of certainty with regards to structural stability and water ingress.

“We are also currently six advances away from the back of LU’s passenger tunnel down at the interchange between the District and Circle line and the Victoria line. Very soon we should have exposed the back of LU’s existing infrastructure, and then it is more of a delicate operation to install the strong backs and frames to stabilise existing assets to allow us to construct  the opening.

“TWBN spent a lot of time re-designing junctions to make sure we didn’t have to put props in the public area of the tunnel, given how busy Victoria is – particularly at these critical locations.”

North ticket hall

A key element of the upgrade is to build a new three-storey North ticket hall beneath

Bressenden Place, a major road that has had to remain open throughout the works.

To deliver this, the partners have developed a solution using top-down construction for both the new ticket hall and extension to the existing one. This will be achieved by building it in two halves, starting at the roof and excavating to create each level as they work downwards.

This method should minimise the extent of temporary propping required, while constructing the new ticket hall in two halves will also help keep traffic flowing by allowing the road to remain open at all times.

Construction of the reinforced concrete slabs at ticket hall first basement level is complete, and works have moved onto the excavation of the plant room.

Prangley added: “Since 2013, we have finished the piling, formed the ticket hall roof, and have excavated and built the ticket hall slab.

“We are now a few weeks into the excavations for the plant room, and  we are about 30% through that excavation. For two-thirds of the box, that’s the final level, with a deeper section  where the escalators drop down to make the connection into the tunnel  one more level down. The team are striving to complete the next level, which is key to unlocking the rest of the project towards the end of September.”

Service diversions are ongoing as part of the enabling works for the Cardinal Place entrance to the ticket hall, and the partners expect to have all of these diversions completed by early July. This will allow them to commence the first phase of construction of this new entrance, and works will commence with secant piling. 

The plan is to finish the civils work by the end of this year

“We have a very critical possession for a blockade around Christmas, which is to form the link under the District and Circle line – PAL 6 in our plans – which is a key milestone that’s already fixed in LU’s blockade plan. The real thing is to move away from the civils and into the fit-out element of the works for both of the ticket halls at the end of the year,” Prangley said.

Upgrade legacy

The project is longer than the average job, which usually lasts no longer than two-and-a-half to three years, and the JV is already four years in. Prangley said “We are proud of the project and continue striving to exceed our client’s expectations, whilst delivering a crucial improvement for the Victoria area.”

Keelan added that one of the main plus-points on the upgrade is that it has not been delivered in isolation from the network. Instead, he hopes it will serve to enhance performance overall in line with its sister projects at Bond Street and Tottenham Court Road.

“The work we do here in enabling people’s movement in and out of Victoria Underground station and in terms of enabling their interchange should allow the Victoria Line Upgrade to reach the target of 36 trains per hour,” he added.  “So far the project has delivered many milestones and we hope to deliver many more.”

BIM on the Victoria Station Upgrade

Extract from Institution of Civil Engineers case study:

“To manage the daunting challenges and risks of VSU, the project team is using building information modelling (BIM) on a scale that was unprecedented in the UK when work got under way in 2006 and remains exceptional. BIM is a process that incorporates 3D design, simulation and analysis, quantity surveying and a host of other tools, and provides a platform for collaboration. LU initiated this approach because without a spatially accurate, fully co-ordinated 3D model it would be near impossible to visualise and co-ordinate the project. The model was an engineering requirement.

“VSU is being delivered by TWBN under an NEC Option C design and construct contract, with shared gain/pain. Mott MacDonald developed LU’s concept design, helped steer the project through the statutory Transport & Works Act processes and is now working as the designer for TWBN.

“…When design got under way in 2006, VSU pushed the use of BIM far beyond anything previously attempted in the UK and set standards internationally. Use of BIM on the project predated the government strategy. Indeed, VSU was a reference point during development of the strategy and remains an exemplar in terms of information model maturity.

“…Time and cost savings are being delivered by using the integrated BIM model to check for structural, architectural and building services clashes within the station. On design of the ticket halls, automation within the model has yielded time savings on structural recalculations required following architectural changes. For example, when changes were made to the position of openings in structural slabs, the model calculated the new load paths and regenerated the reinforcement design with minimal rework.

“Quantities of materials are automatically calculated by the model, giving visibility to the cost impacts of design changes.”

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