1.1 Introduction
Geological assessments on the excavated rock slopes are to assess the geological conditions with respect to rock slope stability of the in situ rock mass.
The assessment usually includes measuring the orientation (dip and dip direction) of the prevailing discontinuities in the rock mass that are related to slope stability.
Subsequently assessment on the conditions of proposed slopes using appropriate methods and computer software is under taken and lastly to recommend the appropriate methods for stability improvement if unstability conditions occurs. This assessment is important to get the first presentation of the geological data in a form which can be understood and interpreted by others who may be involved in the stability analysis. In this study geological data pertaining to the orientation of discontinuity planes present in a cut slope is used to assess the stability of the slope.
This is due to the fact that discontinuity planes are the main factor that contributes to the unstability rock slope particularly of those that display fresh to moderately weathered condition. There geological data also important as it dictated the mode of failure, which in return is relevant to the determination of methods of stabilisation.

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1.2 Statement of research problems
Mode of failure in rock slope can be determined based on the orientation of the discontinuity planes and weathering grade of the rock mass. These two important aspects can be assessed on site during preliminary site investigation. Data collected can be used to assess the potential unstability and mode of failure in the cut slope.
The mode of failure in particular is essentially important for determination of effective stabilisation method.
1.3 Objectives of the research
In general, this study is aimed at achieving the follow objectives; i) To understand the in-situ geological conditions and related field assessment in evaluating the stability of rock slope. ii) To assess the stability of rock slope, specifically on mode of failures using computer software. iii) To recommend suitable methods of stabilisation based on modes of unstability.
1.5 Research methodology
A site at Bukit Ubi, Kuantan, Pahang, has been used as a case study for this project. Relevant data and information collected during the field assessment of the site, which include site investigation and geological assessment (weathering grade and discontinuities orientation), have been used to assess the stability of the cut slope in the area. Related rock parameters used for stability analysis was adopted from laboratory test conducted on the in situ rock. Thorough literature review was undertaken in order to gather understanding on the mode of failure in rock, methods of stabilisation and weathering grade.

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1.5 Scope of research
In order to achieve the mentioned objectives, the scope of research will be focused on the following aspects; i) In-situ geological conditions which are easily recognized and measured, and these include weathering grade and orientation of plane of discontinuity. ii) To assess the modes of failure, the discontinuity planes being considered is joint plane and weathering grade from Zone I to Zone III. iii) A cut slope in Project Bukit Ubi, Kuantan, Pahang will be used as a case study. The construction project that will be conducted at this site is
“Projek membina dan menyiapkan 2 buah tangki air konkrit bertetulang”.
Data used in this study is based on the geological assessments conducted at the project site.
1.6 Research hypothesis.
For the rock mass that displays weathering zone of Zone I to Zone III, its stability will be controlled by the presence of discontinuity planes. The orientation of there discontinuity planes such as joint can be used to assess the mode of failure of the rock mass when free face (e.g. slope) is created in the rock mass. Mode of failure, in returns can be used to determine the method of stabilisation the slope.