CampbellReith was appointed to provide full engineering services for two large five storey buildings that are connected with a podium garden at second floor level. This includes a carpark from ground to first floor and office/laboratory from second to fourth floor.
The superstructure comprises a steel frame and precast concrete plank floors, where the internal beams are set within the depth of the slab (slim floor) and the edge beams are set below. The internal ceiling space offers a flat soffit to provide maximum service flexibility for the laboratory.
The structural grid alternates between 9.6m x 11.2m and 9.6m x 6.4m, minimising internal columns and to suit the lower level carpark layout. The stability of structure is provided by a combination of moment resisting frames and vertical bracing/braced walls. External elevations are to be unobstructed by bracing, and so are made into sway/moment resisting frames, and the core consists of vertical bracing hidden within stair core walls etc.
The foundations consist of ground beams spanning between pile caps, that are supported on deep bored concrete piles extending down to approximately 25m on average due to poor soils.
The drainage networks to the site are drained by gravity. Surface water discharges into the Littlemoor Brook, and foul discharges into the existing private system and pumping station nearby.
Permeable paving is used for the ground finished surface to collect rain water and direct to suitably sized attenuation tanks prior to being discharged to the brook.
Other principle elements of the project brief and factors that have been considered in developing the civil and structural designs include:
- Providing structural allowance for a future bridge structure connecting the second floor podium garden to the proposed train station to the north.
- Vibrations limited to response factor R<4.
- Lift shafts are considered independent precast stacked tower structures, designed by specialist. The lift pit is also precast concrete, with all waterproofing provided by the manufacturer.
- Future “M&E” plant space is provided. internally to all floor plates and within the roof top plant enclosure.
- External terrace space is located at fourth floor level overlooking Littlemoor Brook.
- Ground floor reception is located within a two storey Atrium in each building.
- Roof structure consisting of metal decking and long span beams over fourth floor office space, with service integration provided by large diameter cell voids at regular centres.
- Structure designed to support terraced landscape linking the brookside walk to the second floor podium garden, where rainwater storage is provided below feature planting and paving.
- Movement and construction phasing has been considered to address expansion and contraction in this very long building.
- Vehicle tracking has been used to check accessibility within the car park and the wider site generally.
- Managing flood risk and flood compensation as site is within Flood Zone 2.
Photo credit to Perkins&Will.