Урок 4.2

Текст A

SOUTH HOLLAND CENTRE, SPALDING, ENGLAND

Generally the building has cast-in-place concrete floors supported by brickwork walls and columns, although outside, on the north-west elevation, the six columns and the two large columns on either side of the entrance are concrete with a brick surround and in the middle unit of the building, the floor of the main hall is precast concrete.

The structure of the middle unit consists of two 381 mm thick brick cavity walls with the main hall floor and roof spanning them. These side walls are buttressed by piers at 4.21 m centres giving an overall depth at pier positions of 954 mm; the main hall floor consists of prestressed precast concrete floor units, with a 50 mm cast-in-place topping; adjacent units are welded together by means of steel inserts at 2.40 m centres along the edges, the floor thus forming a rigid diaphragm. The strip foundations to the side walls are taken below a soft clay layer to sand. The stability of the whole middle unit of the building is assured by four 225 mm thick return walls, about three metres long, on one side or other of the wall on the south-west elevation, all being founded on the same wall strip; the two inner return walls terminate at the main hall level. All other ground floor walls at right angles to the side walls are separated from the main loadbearing walls by vertical movement joints and have separate strip foundations. The back unit of the building is similar in principle to the middle unit but the two loadbearing walls run across the building in a north-west direction with cast-in-place floor slabs spanning between them; at the hall level, the slab cantilevers over the wall on the south-east elevation. The foundations for these loadbearing walls run in a continuous strip under the four walls of the unit with a minimum width of 2.35 m.

The front unit of the building is founded on a 450 mm concrete raft at basement level which is stiffened by concrete basement walls that in general are 300 mm thick. This was necessary because the unit contains a number of structural forms which all work together and cannot withstand differential movement. The concrete columns on the north-­west elevation appear to be separate but, although they rest on strip foundations outside the raft foundation, they are in fact tied back to the basement by concrete shear walls below ground level and this prevents differential movement.

Notes:

buttress v. поддерживать

insert n. закладная деталь

soft adj. мягкий