(Continued from previous page)
this floor acts as a spacer for the tension frames on which the cables in the main beams are tensioned.
After the roof slab has been cast and the penthouse which houses the lift machines, tanks, etc. has been built. the first process of work, which has only to be done once, is completed and the industrialised phase commences.
The upper part of the supporting walls between roof slab and jacks is built up of high quality concrete blocks bounded homogeneously with an infilling of rapid hardening con. crete. In the Coventry building the supporting core consists of eight wall panels each on a group of five jacks. Before the walls are jacked up, each panel is temporarily pre- stressed in the horizontal direction just above the jacks. This is done. to counteract tensile stresses which develop when individual jacks are lowered for the insertion of blocks.
The jacking is carried out in lifts equal to the height of one block,
ABERDEEN PLAN (from page 87)
The outline plan shows the tunnel from Aberdeen emerging on
the north side of Hong Kong Island below Stubbs Road. From there the road link can be extended to connect with Happy Valley and the future waterfront road.
The proposed tunnel would be about 1,800 yards long. If built, it would reduce the distance from Aberdeen to the Star Ferry to between three and a half and four miles.
Provision is also made for a main road connection to the proposed tunnel. This road could initially be connected with the road at present under construction from Wong Nei Chong Gap.
The outline plan makes provision for the widening and extension of Wong Chuk Hang Road.
Through Traffic
The Town Planning Board recom. monds that direct access to Wong
98
which in this case is 7 inches. The whole construction is lifted to this height, after which each jack is lowered in turn, and a new layer of blocks is inserted one by one. The jacks then lift the core again one more block height. After five layers have been inserted, the blocks are infilled. In each of the two follow- ing days five more layers are built. This completes a jacking cycle in which process the building is lifted one full storey height. The rate of jacking is about 1 inch every three minutes. The jack layout is such that some act as compensating jacks whereby great stability is achieved during the lifting period. and ver tical alignment is assured even in high winds.
After completion of a jacking cycle, tensioning takes place at ground level. the next floor is cast. covered in with slabs, and the necessary finishing materials placed on the floor. As the building is extruded from ground level. it passes through each of the various finish- ing stages, where the same processes are repeated at the same height.
Chuk Hang Road should be restricted throughout its length and limited junctions with town development roads have been desigend to facilitate through traffic.
A high level road which will pro- vide a new access to the Cemetery has also been planned.
Several new roads, including two to connect Wong Chuk Hang Road with Brick Hill and Ap Lei Chau. are also shown on the draft plan.
The outline development plan lays emphasis on the construction of footways to relieve congestion on the roads and to provide safe and more direct routes between focal polints.
Network of Nullahs
The reclamation and the typhoon shelters proposed in the plan will deviate and restrict the currents of Aberdeen Harbour and Channel.
Further detailed investigation will be needed to deal with the possibility
The whole set-up resembles a tical assembly line.
ver-
The activities on the floors at ground level have already been described, but as soon as the floor has been sufficiently jacked up, the electricians begin their work attach- ing the ceiling fittings under the floor. At first storey height, parti- tions are placed in position, walls are bricked up. floor screeds and plumbing are put in. and frame for the facade covering assembled. See the caption to the first pictures and section for full
of sequence
finishing trades. From fifth storey level each floor rises, complete and theoretically habitable, to its final height.
Two platforms of steel scaffolding clad in transparent polythene sheet- ing make a light air-conditioned factory through which the building passes. The remaining working levels already lie within a closed building of glass and facade cover- ing. With this method of building the influence of weather conditions is practically ruled out.
of nuisance from floating refuse and a canal or culvert may have to be provided.
Drainage has been planned to form a network of nullahs which will connect with the main canal the or the sea. The nullahs are intend- ed to act as interceptors for surface. water drainage.
A site has been reserved for a pumping station on the reclamation to the west of the proposed Town Centre. A site is also reserved for a screening plant at the northern end of the western breakwater.
The Shouson Hill sewerage system, the Board recommends, should be connected with the Aberdeen sewer- age scheme.
The Board states that it will be possible to increase the fresh water supply when the Shek Pik water scheme is in operation but that a new distribution system will be required.
A salt water supply be provided for flushing purposes is also.
THE HONG KONG & FAR EAST BUILDER - VOLUME 18, NUMBER 1