CIVIL ENGINEERING AND PUBLIC WORKS
EARTHWORKS AND PAVEMENTS FOR KUALA LUMPUR AIRPORT
W
HEN it was decided that the in- ternational airport serving Kuala Lumpur should be capable of tak- ing all aircraft in present use and al- so those aircraft which would be in use in the foreseeable future, it was found to be preferable to construct a new airport rather than enlarge the existing one, since (a) the present air- port has very bad aeronautical fea- tures; (b) all the existing pavements would need strengthening; and (c) the present terminal building would be inadequate.
The search for a new site reveal- ed that there was only one area with- in 15 miles of Kuala Lumpur where a new airport could be constructed with obstruction-free approaches. This site is approximately 13 miles to the west of Kuala Lumpur and is quickly and easily reached via the main Kuala Lumpur to Klang high- way. The airport site has now been connected to this highway by means of an underpass and approximately 31⁄2 miles of dual carriageway ap- proach road.
The layout finally adopted for the airport and the one constructed is given in Fig. 1. The layout comprises a single runway with a full length parallel taxiway on the eastern side. High speed turn-offs have been incor- porated in the design and the layout provides approximately similar land- ing conditions from both ends.
Wind velocities recorded at points near the airport site indicated that the specified cross-wind component would not be exceeded by constructing the runway on the line which provided the best obstruction-free approaches.
The main parking apron was con- structed to accommodate five large and three medium sized planes in the first instance. The apron can be ex- tended if required but in the mean- time a portion of it can be used for overnight parking or as a holding area for the southern end of the run-
way.
A holding area was constructed for the northern end of the runway and this too can be extended if required. Subsidiary parking aprons were also constructed in the maintenance area and the private hangarage area. Se- parate taxiways were also provided to these areas from the main parking
apron.
It was decided that the main air- craft pavements should be construct- ed to a load classification number of
Far East Architect & Builder May, 1967
This feature is published by kind permission of the Institution of Civil En- gineers, London. It is based on a paper presented to the Institution by Mr. H.G. Skep- per, MBE, B Sc, MICE, of Ove Arup and Partners, for- merly assistant director (de- sign, research and training) PWD, Malaya; Mr. H. Rook, MBE, B Sc, DIC, AMICE, John
Laing Construction Ltd., formerly superintend- ing officer and resident engineer; and Mr. Wen Hui Ting, BE, MS, AMICE, Chur- chill College, Cambridge, formerly engineer, PWD, Ma- laya.
The paper gives briefly the reasons for the choice of the type of construction used and describes three important aspects of the construction, namely the earthworks and compaction, construction of the stabiliz- ed soil working bases and evaluation of the strength of the completed pavements.
100.
Consequently the appropriate equivalent single wheel loads at pres- sures of 100 lb sq. in. and 250 lb/- sq. in. were examined. These examin- ations indicated that the e.s.w.l. at a tire pressure of 250 lb/sq. in. would be critical up to a depth of about 16 in. after which the heavier e.s.w.l. at the lower pressure of 100 lb sq. in. was more critical.
Design
Earthworks
An examination of the site showed that an airstrip could be constructed for a 12,000 ft. long runway having approaches completely free of ob structions and it was decided to con- struct the earthworks for such a strip. After further consideration it was, however, decided only to construct a paved runway 11,400 ft. long in the first instance.
The chosen site comprised two distinctly separate areas. The area to
the north was low-lying and flat in nature and was occupied by a Chinese village whose inhabitants had cul- tivated the land and had also con- structed earth bunds to form ponds for breeding fish. The area to the south was under rubber cultivation and was hilly. It was planned to level these hills to provide fill material for the rest of the site.
A geological report of the north- ern area by the Geological Survey Department indicated that the soils had been formed by the weathering of sedimentary rocks of the sandstone and shale series which were overlain by recent alluvium. Bores put down in this area revealed layers of soft material of varying depths but con- solidation tests on samples from these layers indicated that consolidation of these soils would be largely completed during the construction of the fill which was to be placed in this area. Extra soft pockets of these soils were, however, planned to be removed and replaced by selected fill.
The soils in the hills in the southern area were, according to the geological report, derived from the weathering of granite.
Immediately prior to, and at the commencement of, construction of the earthworks a further analysis of the soils to be used as fill material was carried out and it was discovered that it was possible to classify the soils into various types using the soil classifica- tion test results. The various types classified are given in Table 1. as are their typical properties.
It was also found possible generally to identify the various soil types by means of their vertical distribution and colour. Type I soil was found at the top of the soil profile and was yellow. Type 2 soil was found im mediately below Type 1 soil and its colour was yellow with red mottling. Types 3 soil was found below Type 2 soil and its colour ranged from yellow to a mixture of pink, white. yellow, orange, purple and other
colours.
As there was an overlapping in the colours of the Types 1 and 2 soils a further means of identifying these two soil types was found to be by the amount of silt in the fraction of soil passing the B.S. 200 sieve. The Type 2 soil was found to have a silt frac- tion of less than 70% of the com- hined silt and clay content, whilst found to have a Type 3 soil was
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