THE SCHEME
Located minutes from Canary Wharf, The Madison will rise to 53 storeys, delivering 423 new homes and an extensive public garden. Property developer, LBS Properties, appointed Bachy Soletanche as the Principal Contractor for the initial phase on this landmark development.
Bachy Soletanche’s contract included the delivery of the enabling works, along with the design and installation of the piling package. The brownfield site previously contained an office block which, prior to the team’s arrival, had been demolished, leaving the site ready for the enabling works to commence.
ENABLING WORKS
Prior to commencing the piling, a number of activities had to be untaken which included; coring and backfilling of existing piles, coring and plugging of an old Victorian sewer, installation of sheet piles, installation of the piling platform and the construction of guide walls for the retaining piled wall.
In addition to this the team had to manage the removal and relocation of a gas governor from inside the site boundary to a new point on the edge of the site.
CONSTRUCTION
Following the completion of the enabling works the team set about installing the geotechnical package. There were three elements to the scheme which included a secant piled wall, contiguous piled wall and bearing piles. The secant wall, formed from 368 piles, was 234m in length and bored to a depth of up to 20m – the piles were installed using a BG46 piling rig in CSP mode. The contiguous wall, formed from 149 piles, was 150m in length and bored to a depth of up to 20m. Finally, the team installed 109 CFA bearing piles, bored to a depth of up to 24m.
The reinforcement used in the CFA piles was plunged to the cut-off depth, which in some cases was up to 12m below the ground level. This approached allowed for reduced rebar usage and made the cut-off process far more efficient as there was no requirement to cut through the steel rebar when breaking down the pile.
Bachy Soletanche’s ability to operate as the Principal Contractor was key to the contract award and involved several additional responsibilities, these included; overall site management and security, health and safety of all personnel on site, client liaison and community engagement.
This experience was invaluable to the client and ensured that the site was handed over to the follow-on trades for the main structural build to commence for the Madison Tower.
