THE SCHEME
Bachy Soletanche carried out the piling on the grade separated interchange on the A41 in West Bromwich for a Balfour Beatty / Birse JV worth £2.5 million, the piling project consisted of 600 linear metres of heavy duty Continuous Flight Auger (CFA) and Cased Secant Piling (Cased CFA).
The works were planned to ensure minimal disruption to the travelling public.
DESIGN
The hard / hard and hard / firm secant CFA piles were 600, 750 and 900mm diameter up to 18.5 metres deep, were designed by Sandwell Metropolitan Borough Council’s engineer, Scott Wilson Limited, and include reinforced primary (female) piles in the over-bridge wing walls. Bachy Soletanche proposed the use of a Cased CFA Secant Piling solution, as an alternative to conventional large diameter rotary piles to improve production and equal verticality tolerances.
CONSTRUCTION
Due to the 18.5 metre pile depth Bachy Soletanche’s biggest rig, a BG40, were used for the Cased CFA secant piles with the remaining shorter smaller diameter piles being installed by a CM70 rig. Once complete, the retaining walls formed the new underpass beneath the newly aligned roundabout so as to improve traffic flow on the A41.
The work was carried out in line with strict Health and Safety regulations and the JV between Balfour Beatty and Birse worked hard to limit the disruption to the travelling public, so as little disruption to commuters to occur as possible. The piling works were carried out in two pre-planned phases over a total of twelve months, to suit the site programme and available work areas. These were planned to avoid unnecessary disruption to local residents and traffic and the different rigs were used for the various stages to optimise the pile productivity.
