Downe Hospital is a high prestige building forming the shape of an aeroplane with distinctive wings at a 30o angle. This was on a green field site taking up from ground beams to roof level, incorporating columns, beams and insitue floors with a 6m propping level.
The project comprises the construction of a new three-story multi department hospital. Operational units within the hospital will contain the following departments and services:-
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A&E department
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10 bed observation unit
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Outpatients
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20 bed in-patient ward
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Coronary care unit
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Health records
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25 bed acute psychiatric unit
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Day procedures unit
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Clinical support, including physiotherapy and occupational therapy
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Obstetric day care
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Children’s day care
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Pharmacy
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Miscellaneous support services and mortuary
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Dementia block
The superstructure of the new building comprises of a two-story reinforced concrete frame with a lightweight steel portal-framed roof over the plant rooms.
The Level 1 -lower ground floor is also a reinforced concrete frame.
Pad and strip foundations transfer the load to firm stiff sandy gravely clay. In situ concrete flat slab floors have been designed to provide a smooth soffit for the distribution of services. A reinforced concrete retaining wall will provide stability between Level 1 – lower ground floor and Level 2 - ground floor area. Generally a 7.2m x 7.2m and 8.4m x 8.4m structural grids have been used for the column layout to achieve economy of design while not compromising architectural requirements.
In situ concrete floors (including the floor to the roof plant rooms) have been designed as flat slab plate elements supported directly by the columns on the 7.2m or 8.4m structural grid. Floor thickness’ will vary from 270mm to 400mm depending on location and loading, an imposed load of 4.0kN/m² on any floor, other than roof plant room floors which are generally 7.5kN/m². In addition to the imposed loading an allowance of 1.0kN/m² has been made for lightweight internal partitions.
Wind / notional loads were designed in accordance with BS 6399 : Part 2 ‘Code of Practice for Wind Loading’, a wind speed of 24m/s has been used for the design. Concrete shear walls have been designed for a lateral load of 1.5%.
