Dominant weathering profiles of granite in southern Peninsular Malaysia

• Identification of dominant weathering profiles in a tropical region.
• Investigation of characteristics of each weathering zone.
• Proposing two sub zones in highly weathered and completely weathered zones.
• Abrupt changes and corestones were found as significant features in the profiles.

One of the most important challenges in the study of slope stability, foundations, and excavation of rocks is to understand their weathering states. This issue is more important in tropical climates, where severe weathering produces thick weathering profiles with different sequences of weathering. Thick weathering profiles are normally classified or graded, based on field observation, geological studies, and the material properties of the rocks. This paper presents the results of an extensive study of changes in the geological and morphological characteristics of granite in a tropical region due to severe weathering. A total of 40 panels of rock exposure were studied in four active granite quarries located in Johor, southern Peninsular Malaysia. The proposed dominant weathering profiles of granite are mainly based on the sequences of weathering zone, topography and geological conditions, joint characterization, and the dominant color of rock material. In addition, two additional weathering subzones are introduced in the completely and the highly weathered zones based on the presence of corestones (boulders). It is believed that the proposed dominant weathering profiles can contribute to engineering design and the classification of weathered granitic rock in the tropical region.