General geology and engineering geology: rock mass strength of cut slope in and around Kg Lawar, Jeli, Kelantan

Rock Mass Rating (RMR) has found wide applications in various types of engineering projects such as tunnels, slopes, foundations, and mines. The stability of cut slope can be determined from the rock mass rating classification. The objectives of this study to update current geology map of study area to 1:25,000 scale, to determine the rock mass strength of cut slope in and around Kg Lawar, Jeli, Kelantan and to determine stability of cut slope at study area. Geological mapping and discontinuity survey has been conducted on rock slopes in and around Kg Lawar, Jeli, Kelantan. This survey carried out scan line technique and taken into several parameters such as type, spacing, orientation, length, aperture, infilling, surface roughness of the discontinuity and the water conditions in the discontinuity plane. Geographic Information System (GIS) analysis also was carried out to update the map of study area. The data obtained from the discontinuity survey were then used to determine the rock mass strength of cut slope and stability of cut slope in study area. The results showed that the lithology found in Kg Lawar is granite and small occurrence of gneiss. The studied rock masses in study area for slope 1 categorized as a fair rock (rating 47), slope 2 categorized as a fair rock (rating 45), slope 3 categorized as a poor rock (rating 14) and slope 4 categorized as a fair rock (rating 42). The stereographic plots of the discontinuities revealed that most of the rock slopes has a potential to fail either in a mode of wedge and plane failure or a combination of more than one mode of failure.