5 Maxwell Road #05-00, Tower Block MND Complex, Singapore ...
Millbank Tower Block
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January, 1962 3 Structural Engineering Aspects of the Millbank Tower Block, London* by Colin Davies, B.Sc.(Eng.), A.M.I.Struct.E., A.M.I.C.E. Introduction The roughly triangular site bounded tothenorth by Thames House, tothe south-west by The Queen Alexandra Military Hospital, and having a 650 ft. frontage to the River Thames, forms part of an area which in the 18th century was known as Thorney Island-an area of peaty marshland intersected by streams flowing intothe river, and extendingasfar back as St. James’s Park. The Island belonged to the Marquis of Salisbury who in 1799 sold it to the Crown for the erection of what became known as Millbank Penitentiary, the north boundary of which remains as the bounda~ y between the present development and the neighbouring hospital.Fromabout 1860 the site at present being developed was occupied by a mixture of residential properties, mews, industrial buildings and contractors’ yards. In 1955, however, with only three years of the lease torun,the time was thought opportune for demolishing the existing buildings and developing the site commercially, under anew lease from the Crown, with a contemporary architectural scheme. Many schemes were considered, but the most satisfactory from the point of view of civic design, and bearing in mind the planning restrictions, was a main tall block withsurrounding lower buildings and open areas, all physically and architecturally related. Preliminary sketch plans were produced by the Architects, and by 1957 the general massing of the buildings togetherwiththeir individual forms had been agreed, having had approval in principle from the Royal Fine Art Commission and the planning authorities. The project as it is today embraces three main buildings : a tower office block, having 34 storeys in a height of 387 ft. above ground floor, an 8-storey Y-shaped office block and a 12-storey residential block. Included in the surrounding low-level accom- modation linking the three main blocks areathree- tier car park served by a cantilevered spiral ramp, a conference hall/cinema and a three-storey podium. The total building cube is 9 t million cubic feet of which 5 million cubic feet is accounted for by the tower block alone. Except for a limited amount of structural steelwork and precast concrete in the tower the entire development is constructed in in-situ reinforced concrete on deep bored piles. Single-storey * Paper to be read before the Imtitution of Structural Engineers, at 11, Upper Belgrave Street, London, S. W.1., on Thursday, 1 lth January, 1962, at 6 p.m. basements are provided under the tower and Y-blocks and under the north return of the podium ; the boiler house for the whole project is located between the lower ground and first floors of the residential block. Whilst this paper concerns the 34-storey block, which structurally is virtually isolated from the adjoining buildings, some of the details given (especially those relating to piles and concrete) also apply to the remainder of the development. The site is being developed by Legal and General Assurance Society Ltd., for Vickers Ltd. and others. The Architects are Ronald Ward and Partners, the Consulting Engineer G. W. Kirkland of R. Travers Morgan and Partners, the Quantity Surveyors Franklin and Andrews, and the Main Contractors John Mowlem and Co. Ltd. General Description of Tower Block By mid-l957 the shape and size of the tower block envelope were basically settled and have remained almost unaltered since. The plan shape was to be squarish with the right-angled corners turned through fifteen degrees relative to the main centrelines of the building, thus forming concave east and west faces and convex north and south faces. It was the recommendation of the Consulting Engineer that the construction should be mainly in in-situ reinforced concrete, witha stiff central core forming the main structural element for stability against wind, the walls of the core enclosing the numerous vertical services necessary for a fully air conditioned tall building. During some months of close collaboration between all concerned, several preliminary structural designs were prepared on this basis, some of which proved to be unsuitable for one reason or another. The shape of the building presented inherent problems structurally, but such problems were largely overcome by developing the structure as an expression of the architecture, the lay out culminating in that illustrated in Fig. 3. This plan actually represents the 5th to 13thfloors inclusive, but could also cover the remaining floors up to the 30th if the reductions of column size and core wall thickness are overlooked, together with minor variations to the floors inside the core ; in point of fact the structural arrangement and reinforcement details of the floors outside the core are identical in all respects for twenty-six floors. The 4th floor has an additional
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