A21 Tonbridge to Pembury Dualling

The A21 in Kent is a busy arterial route in desperate need of upgrading to accommodate the high levels of traffic. The two lane carriageway between Tonbridge and Pembury was to be upgraded to a dual carriageway, with work commencing in 2015 and due to finish in late 2017. The £70 mill scheme involved the construction of several new bridge structures, with several reinforced soil structures required to form the new bridge bank seats and wing walls, a slip road retaining wall and reinforced soil slope.

The Client's Engineer WSP specified a Tensar TW3 modular block reinforced soil system, with Tensar responsible for the design and supply of the system, with Phi Group contracted by Balfour Beatty Civil Engineering to install several substantial reinforced soil structures. We also designed, supplied and installed a reinforced soil slope using our Textomur system.

In total Phi Group has been responsible for the installation of 6 structures in all, with a face area of over 2,500 square metres.

Fairthorne Underbridge

Installation of 733 square metres of Tensar TW3 block with the placement and compaction of over 5,500 cubic metres of fill material

Longfield Road Underbridge

Installation of 1,050 square metres of Tensar TW3 block with the placement and compaction of over 10,500 cubic metres of fill material

Tudeley Wood Retaining Wall

Installation of 230 square metres of Tensar TW3 block with the placement and compaction of over 800 cubic metres of fill material

East Road Slip

Installation of 650 square metres of Textomur reinforced soil slope with the placement and compaction of over 5,000 cubic metres of fill material

The project was challenging, with the weather playing its part and causing delays for the project as a whole. The operatives on site, led by Ricky Bishop, worked evening and weekends where required to achieve the programme set by the Main Contractor. 'Red Zone' working meant that a non-working Supervisor was required at all times, and only one operation, such as backfilling or delivery of blocks, was permitted in the working area at any one time. This all meant that co-ordination of deliveries etc was important to avoid any delays on site.

Keller in Action

By 2018 Victoria Tube Station will have a new ticket hall with more connecting tunnels that will join the existing parts and new parts of the station together. These have all been constructed in water bearing soils needing treatment. This is the largest jet grouting project undertaken in Europe.

Where we've done it

Our solutions are used across the construction industry from residential development, infrastructure and civil engineering to the energy and resource sectors.