Chilled Warehouse, Bracknell

Hurst Peirce + Malcolm LLP were employed to provide civil and structural design services for the construction of a new chilled warehouse in Bracknell. A suspended ground floor was required, supported on piles to achieve Category 1 floor surface tolerances. However, achieving this quality of surface finish in the open air during the winter months was considered impractical so a novel method was devised to enable the superstructure to be completed, and the floor constructed in a controlled environment.

To permit the erection of the steel frame before the floor slab, steel stubs were cast into the tops of the piles. By using an alignment rig, this was achieved to an accuracy of + or � 25mm in plan. Once the pile concrete had cured sufficiently, the top of the steel stub was burnt off to the desired level and a steel plate site welded onto the top. The steel frame was then erected onto these stubs much earlier than would have been possible if pile caps had to be cast. Cladding followed the erection of the frame allowing the pile caps, edge beams and floor slabs to be cast in controlled conditions. This method saved several weeks on the construction programme.

At Hurst Peirce + Malcolm LLP we take time to consider the whole construction process and the overall effect our details may have. In this instance, the contractor was sceptical about the accuracy of positioning the steel stubs. In conjunction with the piling specialist, it was decided to use an alignment rig which added to the cost of the piling but the added value to the project outweighed this considerably.