No_2_February_1969 — Page 24

FROM PL LEV

2013 P. LEY

19 THE PL LEK

TERAL AL LEV

REF. LEX

48310 PL LING,

LECTII I. LAYİ

Section

11

SHAFT

1

OFFICE

H

STUBAS

ROAD

working platform and loading plat-

form were all carried on 58 three-ton jacks and an extra four six-ton jacks were installed to lift an 11-ton crane on the same hydraulic system.

The feasibility of different framing arrangements for a typical floor was investigated. The diagrid was selected as it distributed the loads more evenly all around the perimeter, which was desirable from an architectural point of view and at the same time provided a stiff floor at a favourable cost.

Diagonal ribs

While this slab could have been designed in reinforced concrete, the high percentage of reinforcement, par- ticularly the compression steel, would have made the placing of concrete extremely difficult. The post-tensioned diagrid avoids deflections due to live load and creep.

The slab consists of 21 in. deep and 8 in. wide ribs at 4 ft. 9 in. centres, run- ning diagonally in both directions and is designed for a dead load of 130 lb. per sq. ft. and a live load of 100 lb. per sq. ft., including partitions and false ceiling, making a total of 230 lb. per

sq. ft.

.

The spacing of the ribs is governed by the mullion spacing of 6 ft. 9 in. and

LIFT

Parking levels below Stubbs Road

22

་་་་

Lm

Far East BUILDER, February 1969