Bulletin of the Geological Society of Malaysia, Volume 80, November 2025, pp. 59 – 81

Rock slope assessment in tropical climates: A comparative study using multiple rock mass classification system

Ahmad Faiz Salmanfarsi, Haryati Awang^*

Faculty of Civil Engineering Technology, Universiti Malaysia Pahang Al-Sultan Abdullah, Lebuhraya Tun Razak, 26300 Kuantan, Pahang, Malaysia

* Corresponding author email address: haryatiawang@umpsa.edu.my

Abstract: In tropical climates, exposed rock slopes are significantly weathered to form extensive weathering profiles. Combined with other factors such as slope orientation, discontinuities, and weather conditions, rock slope conditions need to be monitored for potential instability and failures. Rock mass classification is one of the most widely used empirical methods of classifying rock mass slope properties. Several rock mass classifications have been developed each year based on different rock mass parameters. This paper evaluated various cut rock slopes along Karak-Lanchang, Pahang, which showed potential failure zones from discontinuity sets and weathering zones, using selected rock mass classification systems. The rock slope mapping was carried out using conventional field mapping and Terrestrial Laser Scanning (TLS). Comparison between the mapped discontinuities and the discontinuities extracted from TLS revealed some degree of correlation. From the discontinuities mapping, kinematic analysis identified several potential slope failure modes. The stability conditions of the slopes were determined, and a comparative analysis of the different rock mass classifications was carried out. The paper highlights the significance of the classification results and discusses the contributing factors that affected the results of the various classifications. A more comprehensive classification of rock slopes is presented in this paper by comparing the results obtained from the different rock mass classifications.

Keywords: Rock mass classification, kinematic analysis, TLS, granite, engineering geology

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Manuscript received 13 June 2024;
Received in revised form 22 September 2024;
Accepted 20 February 2025
Available online 28 November 2025

https://doi.org/10.7186/bgsm80202505

0126-6187; 2637-109X / Published by the Geological Society of Malaysia.
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