Balfour Beatty lays the foundations at Blackfriars

Balfour Beatty Ground Engineering (BBGE) – a leading ground engineering specialist, is nearing completion of a ten month foundations project on Network Rail’s landmark Blackfriars station redevelopment.

BBGE is delivering the final stages of complex foundations work to prepare for the construction of the first railway station to straddle the Thames in London as part of the Thameslink Programme. 

The ground engineering specialist mobilised to site following the demolition of the existing buildings, and completed a programme of significant geotechnical works.

The team comprising of BBGE, main contractor Balfour Beatty Civil Engineering and customer Network Rail overcame a number of challenges including working adjacent to a live railway line and above a live Underground track in small constricted spaces.

Additionally, as the site had been developed many times in the past, there were a number of obstructions encountered during the piling work including old brickwork, reinforced concrete and existing concrete and timber piles.  BBGE devised a number of solutions to allow the team to overcome these obstructions.

To overcome the restrictions of working in a confined space and above the live Underground track, a Track Protection Structure (TPS) and a temporary King Post Wall was installed by BBGE and placed above the London Underground tracks to ensure no disruption to existing services and to create a safe working environment. The installation of the King Post Wall allowed the piling platform to be raised to a single level, thereby providing the required safe working space for the large piling rigs without any undue load being exerted on the TPS.

With the TPS and King Post Wall in place for a safer site, a combination of over 700 large diameter secant wall and bearing piles ranging from 600mm to 1000mm in diameter and up to 39 metres deep, with only 6m of headroom in some instances, were constructed. Additionally, there were also self drilled micro piles of 187mm in diameter which were installed up to 18m deep with only 3m of headroom.

Due to the unforeseen obstructions and in order to mitigate delays to the overall programme, double shift working was required and carried out in accordance with Network Rail regulations and with approval from the relevant authorities. This was achieved through careful selection of equipment and techniques whilst maintaining strict control on the environmental impact.

These measures brought about the additional benefit of unrestricted engineering hours for the installation of the piles. Due to the varying obstructions encountered, modifications to tools and equipment were essential; as such, BBGE redesigned the configuration of their augers and casing cutting teeth which resulted in reduced equipment downtime as well as greater certainty of the coring time.

Peter Coulthart, BBGE project manager, said:

“The development of Blackfriars Station is one of the most complex construction projects being undertaken in London. We have worked very closely with Balfour Beatty Civil Engineering and Network Rail throughout the process and early involvement was key to developing the initial solutions right through to the current stage which is nearing completion.”

BBGE, Carillion and the Scottish Prison Service work together for sustainability solutions

Balfour Beatty Ground Engineering (BBGE) - leading ground engineering specialists and part of the Balfour Beatty group - has been appointed by Carillion to provide ground engineering works for HMP Low Moss. 

The piling contract for the construction of a 700 cell prison located in East Dunbartonshire is now nearing completion. The overall project will include the provision of the prison house blocks, office accommodation, staff and visitor facilities, a health centre, education and training facilities, a multi-faith centre, a laundry, kitchen and industrial workshops.

Carillion was awarded the contract which was helped by demonstrating strength of delivering sector leadership in sustainable developments. BBGE was known to Carillion as a leading specialist ground engineering subcontractor committed to sustainable solutions for a number of years. The BBGE regional office and precast pile factory is located circa two-miles from HMP Low Moss. In addition to the proximity to the prison, which aids Carillion’s sustainability delivery by employing local companies, the BBGE precast piles that are being installed consist of a self compacting blended mix of 36% recycled material (made of ground granulated blast furnace slag) and 100% recycled water. The BBGE precast pile factory is the only precast factory in Scotland; as such, these precast piles are an excellent local source for the Scottish geotechnical market.

The Contract, which involves approximately 1000 piles, is currently going to plan and BBGE anticipate finishing the works ahead of the target programme.

Fergus Shaw, Carillion Project Manager said: "The work carried out on site by BBGE has been excellent in terms of safety, skill and commitment to both the project and sustainability."

Cameron Burns, BBGE Contracts Manager, stated: "At BBGE we always look at ways to limit our impact on the environment as much as we can by offering more sustainable solutions through innovations or simply smarter thinking.  One example was the use of suppliers of plant and materials based within 15 miles of the site, even the site labour was sourced within this radius. It has been great working with Carillion who are likeminded when it comes to a strong sustainable approach to projects."