Урок 4.8

Текст A

BANK AND OFFICE BUILDING IN MILAN, ITALY

This seven-storey office building is situated on a corner site between two streets at their junction with a public square.

The ground floor and mezzanine are set back to form an arcade, 8.70 m high, extending round the front. These floors and the first floor are occupied by a bank. The other floors contain individual offices arranged on both sides of a central corridor. Two basement levels provide parking facilities for 40 cars. Two vertical circulation cores, each containing a spiral staircase and three lifts, can be reached through separate entrances on each side of the main hall of the bank and are interconnected on each upper storey by a central corridor. In addition, there is a lift connecting the main hall and the first floor.

The arcades are designed as portal frames, surmounted by a pin-jointed framework stiffened by two concrete cores, the frames following the polygonal outline on plan. Each horizontal part of the cross beams in the portal frames supports two radial beams, 5.90 m apart, which cantilever 1.0 m beyond the cross beams and carry the columns of the storeys above.

These external columns, which are HE 300 B sections, are connected at each upper floor by transverse beams to a longitudinal beam, cranked on plan, which is supported on the intermediate columns. These radial trans­verse beams are interconnected by secondary beams at 2 m centres. A generally similar arrangement of main beams, secondary beams and edge beams occupies the space between the cranked longitudinal beam and the rear facade of the building. The beams are stiffened by horizontal cross bracings. All the structural connections are bolted and are treated as pin-joints for the purpose of structural analysis.

The arcade portal frames are composed of welded I-sections, spanning 11 m. Their height is 8.35 m. The web depth of columns is 600 mm and that of the horizontal members – 710 mm. Each portal frame column has a 60 mm thick base plate held down by four 42 mm dia bolts to the reinforced concrete walls of the basement.

Floor beams carry steel trough decking, plastered on the underside and carrying a layer of tar-bonded crushed rock and 4 cm reinforced concrete topping.

Cranked purlins and straight rafters of I-section (parallel to the external facade) are used for the roof structure. The covering of the roof consists of 0.8 mm copper sheet on softboard.

Notes:

base plate опорная плита

polygonal outline n. многоугольный контур

softboard n. доска из хвойной древесины

tar-bonded adj. связанный гудроном

underside n. нижняя\оборотная сторона