NATURE OF PROJECT: GEOLOGICAL ASSESSMENT
CLIENT: SOLSTRUCT SDN BHD
LOCATION: LANGKAWI, KEDAH
INTRODUCTION
Geomapping Technology Sdn Bhd (GMT) undertook the Geological Assessment for Development of Hotel at Lot 40, Seksyen 4, Bandar Padang Mat Sirat, 07000 Langkawi, Kedah Darul Aman. GMT is responsible in providing services to matters related to geological mapping as part of the requirements from the authorities for approving the project.
Figure 1: Location of study area; cut slope at southward of Tanjung Mali hill
Geological Terrain Mapping (GTM) and Engineering Geological Mapping was conducted in this study area.
GEOLOGY OF THE AREA
Study area consist of three (3) facies of i) thick mudstone, ii), pebbly mudstone and iii) graded sandstone. Bedding of the rock layers dipping to the NE especially on the left side of the slope. The changes of dip direction from NE (N 034 E) to ENE (N 112 E) due to occurrence of fault.
GEOLOGICAL TERRAIN MAPPING & DISCONTINUITY MAPPING
Construction Suitability Map (CSM) aims to guide planner to plan development in less risky areas with less geotechnical constraints. Percentage of the study area based on CSM classification is shown in Table 1. Cut slope at the area cover about 6% of the total proposed construction area. The cutslope height is about 10m and the slope gradient is about 60°.
Table 1: Construction Suitability Map classes and its percentage.
Discontinuity mapping was done along the exposed rock outcrop on slope in the study area. The mapping aims to identify major discontinuity sets and associated potential failures caused by certain orientation of discontinuities.
Kinematic analysis was performed to determine potential planar failures on site. One set of discontinuities exhibit potential planar failure orientation.
CONSIDERATION ON TANJUNG MALI
Tanjung Mali is a geosite within the Langkawi Geopark. The location of proposed development is not part of the geosite protected area. However, all precaution should be taken into consideration to preserve the geosite and any incidence that lead to damage of the geosite shall be avoided at all cost.
Figure 2: The proposed hotel development at study area including existing track at the top of the cut slope, existing cut slope, hotel boundary and existing level that will be lowered by 6.6m – 7.0m. the final reduced level is 5.5m. Tanjung Mali protected geosite is about ~100m from the proposed development area.
Figure 3: Typical cross-section of the proposed hotel location and geosite. 9m height of CBP wall is proposed by the designer. The level will be lowered by 6.6m
