London: M25 Widening Scheme

DAWSON WAM was awarded the contract for the installation of permanent sheet piled retaining walls to allow for the M25 carriageway widening scheme to proceed in 2010. Due to the successful completion of the 4B Scheme DAWSON-WAM were awarded the following 4C Scheme of the works that was commenced in February 2011.

In all over 5,200 linear metres of sheet piles were installed with piles up to 18m in length into Stiff Clays.

Our roles included;

• Organising, receiving and delivery of materials/sheet piles for the retaining walls to a remote yard. Piles were purchased by our client however all other aspects of supply were dealt with by DAWSON-WAM
• Reloading and offloading deliveries of sheet piles within traffic management restrictions (often on nightshifts).
• Installation of sheet piles to design level using DAWSON-WAM piling rigs incorporating our most recently purchased next generation of vibration hammers.
• Complying with both our clients and our own integrated management systems which were adhered to and audited under ISO9001, ISO14001 and OHSAS18001
• Liaison with Our Client, Highways Agency, and other associated bodies in weekly review meetings.

DAWSON-WAM undertook the scheme under the goals set out in its sustainability policy and matched the requirements of the SBBJV sustainability plan and diversity plan for the scheme. The M25 was classed as an environmentally active and sensitive area and strict protocol’s were put in place to ensure as little disruption to as possible to the natural environment and wildlife. We installed piles beside watercourses and to do so we used plant nappies and drip trays to ensure no contamination would go into the watercourses. All our equipment runs on biodegradable hydraulic oil. Also water voles habitat was monitored while piling, to ensure that minimum distress and damage was caused to the habitat and voles.