A Geotechnical Engineering Characterisation of Interbedded Kenny Hill Weak Rock in Malaysian Wet Tropical Environment


Zainab Mohamed

Assoc. Prof., Faculty of Civil Engineering, University Technology MARA, Malaysia.
e-mail: hjhzm6@yahoo.com

Abd Ghani Rafek

Assoc.Prof, Faculty of Science and Technology, National University of Malaysia.
e-mail: aghani@pkrisc.cc.ukm.my


Ibrahim Komoo

Professor and Director, Institute for Environment and Development, Nat. Univ. of Malaysia.
e-mail: ikomoo@hotmail.com


An attempt to quantify the geotechnical properties of interbedded Kenny Hill weak rock mass requires an integrated knowledge on the principle of rock and soil mechanics. A Kenny Hill formation is widely found within the vicinity of Kuala Lumpur, which is dominated by interbedding of sandstone and shale. An engineering field mapping was carried out to document the mode of physical deterioration of both rock materials as a unit rock mass subjected to Malaysian wet tropical environment. A systematic approach of the method of characterisation was developed for sandstone and shale that was known as a weak rock. A series of laboratory index tests were proposed for quantifying the qualitative deterioration of these two rock materials. Sandstone and shale characterisation by hardness, texture, jar slake and slake durability were carried out followed by a uniaxial compressive strength and a point load tests. From the extensive effort it can be summarised that as for weak rock, the method of geotechnical characterisation should be best carried out using test procedure that require the least sample preparation. This paper highlighted the outcome of a systematic design approach adopted to meet the objective. A comparative study showed that the geotechnical properties of these two rocks are extremely different forming a heterogeneous rock mass. Thus more than one method of testing with modified approach is required in order to obtain a higher degree of laboratory results.

Keywords: Weak rock, engineering testing, Kenny Hill formation, interbedded rock mass

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