BAUER Technologies, a subsidiary of the BAUER Group, has been awarded the main piling works design and construct package at Principal Place Residential in London, which is a new mixed-use development being developed by a Joint Venture between Brookfield Property Partners, Concord Pacific and W1 Developments.
This award by Main Contractor Brookfield Multiplex Construction Europe, follows BAUER’s successful completion of an Early Works package, where BAUER installed 25no. 1200mm and 1500mm diameter piles over 50m deep in secant pile walls. These piles have a combined structural function as bearing piles for a 50-storey residential tower and as retaining walls for the new Network Rail ‘8-track’ corridor. The installation of the Early Works was complex, requiring BAUER to work next to live Network Rail assets on a designed steel gantry structure constructing piles under bentonite. Working on a steel gantry demanded the use of bespoke piling rig configurations and rigorous adherence to agreed Method Statements. The Early Works scope also included coring of sub surface obstructions, forming guidewalls and the installation of 1800mm diameter bitumen coated, permanent steel liners.
With an overall contract value of £5million, including the Early Works, the main works scope requires BAUER’s BG40 and BG30 piling rigs to construct 27no. 1350mm and 2000mm diameter bearing piles under bentonite for the main 50-storey residential tower and includes the installation of 14no. large section ‘plunge’ columns. For the smaller structures BAUER will install 26no. 880mm rotary piles, while the 15-storey adjacent residential building will be founded on 36no. 900mm diameter, 27m deep CFA bearing piles. As the project will be constructed using a ‘top down’ method to form 3 levels of basement, the 150 linear metre site boundary is supported by a load bearing 880mm diameter secant bored pile wall.
The installation of ’plunge’ columns under bentonite in bored piles demands the use of a specialised temporary guideframe and careful execution of robust work plans at all stages of construction to achieve extremely tight tolerances. As part of the deployment, BAUER will use an ‘on-top reaming’ tool. This is a new drilling tool developed on a previous international BAUER project that is designed to maximise pile diameter where temporary casings are used.
The Principal Place Residential project, which commenced with Early Works in July 2015, is expected to be substantially complete by 2019.
Speaking about the project, Martin Blower, Managing Director of BAUER Technologies, commented: “This is an exciting and prestigious project for BAUER in the London Private Residential market. It requires us to construct piles to extremely tight tolerances in difficult ground conditions. The many challenges that the project presents also give us an ideal opportunity to demonstrate the capabilities of BAUER and our newly developed ‘on top’ reaming tool.”