CIVIL ENGINEERING & PUblic woRKS
Breakthrough on Shek Pik Tunnel
RILLING on one of Hong Kong's D
largest tunnelling schemes was completed on August 23, with the breakthrough of the 12.500 ft. tun- tel beween Shek Pik and Tung Chung, on Lantau Island. Work has been in progress since January, 1964.
More than 600 men worked shifts to drive the 161⁄2 ft. dia. tunnel which will supply Shek Pik reservoir the Colony's biggest at present with water from Tung Chung, on the northern side of Lantau.
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When lining work is complete in April next year, the HK$23 million tunnel will play an important part in the Shek Pik water scheme.
Construction is being carried out by Paul Y. Construction Co., Ltd. The consulting engineers are Binnie and Partners.
Tunnel lining will be concrete, al- though at present steel ribs are being used to support the arch after drilling, since more than one fifth of the tun- nel is made up of "bad" rock.
Another obstacle encountered in the tunnelling was ground water, which amounted to about 2.5 million gallons daily in the horse-shoe shaped tunnel. This was channelled into the reservoir.
Drilling was done by jumboes and Gelenex, a specially designed explo- sive, was used for the blasting.
Other schemes are under way to divert streams from the north side of
the island into Shek Pik, and this has brought about a problem of a dif- ferent kind.
The problem is that the existing bell mouthed spillway on the earth- wall dam was designed with an ade- quate safety margin for floods but not to handle the additional area to be drained into the reservoir.
It has now become necessary to enlarge the discharge capacity of the
spillway to prevent damage to the wall through erosion, and a circular siphon is to be built on the spillway.
The siphon, to be constructed around the top of the existing spill- way, which itself will be modified, is the first of its kind in Hongkong, although others have been used suc- cessfully in other parts of the world. Tenders were called for construc- tion in August.
Members of the construction team pictured at the breakthrough ceremony.
CERAK
Far East Architect & Builder September, 1965
ZEISSL PILING
24" & 20" DIA
CAST-IN-SITU CONCRETE PILES
TUBE EXTERNAL DIA.
NORMAL LOADING CAPACITY
151 TONS
24" DIA.
20" DIA.
105 TONS
Zeissl (Hong Kong) Limited
Piling Site Investigation Engineering
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Room 307A, Great China House,
14-14A, Queen's Road Central, Hong Kong.
Telephones: 237282, 242944.
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