world news
NZ$3 million university building contract
A contract worth almost NZ$3 million for additions to Auckland University has been awarded to Cubitt Wells Ltd. To be carried out for the Ministry of Works, it covers the third stage of a complete new science complex comprising a plasma physics block, a physics-mathematics block and a library, all under one roof.
The section containing the first three floors, each with an area of 3,716 sq. m. (40,000 sq. ft.), covers the entire site. Rising from third-floor level
Science complex for Auckland University
is a 17-storey tower block providing floor areas of 650 sq. m. (7,000 sq. ft.). The total floor area of the building is 15,793 sq. m. (170,000 sq. ft.).
Precast concrete construction will be used for the building, which is scheduled for completion in September, 1971.
Industrialised flats to be strengthened
Following the progressive collapse of a block of industrialised flats at Ronan Point in London, the Greater London Council has now adopted a scheme for strengthening its 29 tower blocks built by the same system.
The strengthening method has been agreed in conjunction with Phillips Consultants Ltd., follow- ing experiments on an unoccupied block. Gas has already been taken out of the blocks and will not be put back.
The method will increase the strength of the wall to floor joints by bolting steel angles to the units at certain junctions. The intention is to pro- vide a tensile resistance at each floor level, in both
directions, of more than 1,500 lb. per ft. and also to ensure that all the panels and all joints at floor level will withstand the effects of the stated pres- sure of 21⁄2 lb. per sq. in.
The advantage of the type of anchor fixing to be employed is that the holes are cleanly and pre- cisely drilled to the correct depth where required without undue noise and with practically no damage to decorations.
The pre-drilled steel angle is supported in its final position and used as a template for drilling; the anchors are inserted to the correct depth and are expanded to an automatically controlled extent by the insertion of a parallel plunger into the tapered bore of the anchor with the aid of a purpose-made 'drift' which ensures that the plunger is driven to the correct depth only.
The clearance between the 3⁄4 in. diameter bolt shaft, projecting from the threaded anchor, and the 1 in. hole in the concrete and in the steel angle is taken up by a ‘tight fitting' packing sleeve. Bridge construction causes problems
Temporary works for the A$16.5 million West- gate Bridge over the Yarra River, Melbourne, have involved some interesting but complex engineering problems.
The contractors, John Holland Construction Group, called in the country's main scientific body, the Commonwealth Scientific and Industrial Re- search Organisation (CSIRO) to help overcome dif- ficulties related to the unusual construction tech- niques for the bridge approach spans. The main problem concerned the lifting of pre-cast concrete sections, weighing up to 110 tons each, into posi- tion on the spans using mild steel erection trusses. The CSIRO Division of Building Research in less than a fortnight made a A$1,000 brass model of a truss to test a design proposed by the contractor.
On each side of the river, it was proposed to have a 400-ton truss (fabricated into plane sections for on-site erection) and each would be required to support 2,000 tons of concrete units over a 220-ft. span while they were fixed in place. A 120-ton over- head electric travelling crane in each truss would lift the concrete segments into positon, where the joints between them would be concreted, steel cables
Model made by CSIRO Building Research Division
Far East BUILDER, May 1969
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