August_1965 — Page 3

Far East

ARCHITECT & BUILDER

The oldest trade journal in the Far East

EDITOR: A. G. BARNETT

AUGUST 1965

news review

Contents

New Review

37

World News

43

Prince's Building, Hong Kong

48

Freedom Centre, Seoul

56

Proposed National Capitol for Philippines,

by Federico Ilustre

61

Toronto City Hall ..

64

Fashions in Art and Architecture, by

Cedric Astbury, FRIBA

69

Civil Engineering Section

Power Company to Build on Tsing Yi .. 71

Dunman Road Bridge and Extension,

Singapore, by P.M. Absolam

72

New Materials and Equipment ..

75

New Contractors' Plant

79

83

85

87

Building Plans Approved

Contracts Awarded

Books

Cover picture:

:

:

North face of the new Prince's Building, Hong Kong, showing the pedestrian bridge which connects the first floor shopping arcades with those of the adjacent Mandarin Hotel. Prince's Building is described page 48.

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Published monthly by Far East Trade Press Ltd., 1908, Prince's Building, Hong Kong. Tel: 241031 European Office: Building and Contract Journals Ltd., 32 Southwark Bridge Road, London, S. E. 1. Tel: Waterloo 2060. Printed by Shum Shing Print- ing Co., 7 Ship Street, Hong Kong. Tel: 724513.

Controlled circulation to 5,000 qualified readers

Far East Architect & Builder August, 1965

LEANING TOWERS OF MONGKOK

MAIN causes of the settlements in some buildings observed in the Mong Kok district of Kowloon last year were the influence of adjacent construction work, con- solidation and water table drawdown, in that order of importance. But, with possibly two exceptions, there was no danger of instability.

These are the conclusions drawn by Mr. P. Lumb, M.Sc (Eng.), AMICE, FGS, senior lecturer in civil en- gineering. University of Hong Kong, in a report sub- mitted to the Director of Public Works on the causes, ex- tent and severity of the settlements. The report is now on sale in the Colony, price HK$4.

Mr. Lumb was the leader of a research group of 16 engineering graduates of the University of Hong Kong who carried out investigations into settlements in con- junction with officers of the Public Works Department. The investigations, which began in the middle of July 1964 and lasted until the beginning of October the same year, consisted of site surveys, examination of record and laboratory testing.

The effects of the settlements were most pronounc- ed in the cases of pre-war buildings on spread footings where severe structural damage had taken place in six cases and severe architectural damage in a further seven cases. In all cases of piled foundations, including short timber piles, the effect of the settlements is a block tilt- ing which, with possibly five exceptions, is "unsightly but not unsafe.”

PRECAUTIONARY MEASURES

In August 1964 bench marks were established on most of the affected buildings in the area and levelling surveys made at monthly intervals to determine whether or not settlements were continuing. The results of these surveys up to January 1965 showed that settlement had stopped in most cases.

The reports states: "Settlement due to drawdown has ceased, due to the re-charge of ground water since July 1964. This re-charge has apparently caused a small amount of swelling of the soft clay layer and some build- ings show a definite but small rise in level. The rise is only of the order of 4 in. and will never reach any ap- preciable magnitude or cause any damage."

On precautionary measures to be taken when con- structing new tall buildings in the area. Mr. Lumb re- commends that the foundations should be long piles driven through the soft compressible clay layer into the residual decomposed granite below, and as a rough work- ing rule the penetration into the decomposed granite should not be less than the thickness of the clay layer.

He also recommends that wherever possible, a gap should be left between new and adjacent old buildings in order to prevent damage to the old, since some slight settlements are unavoidable. "Attempts to arrest settle- ment by grouting the soft clay layer are quite useless and should not be considered.”

Mr. Lumb points out that the fact that three-quarters of the cases of damage were attributed to the effects of adjacent construction and to consolidation under the self

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