Evaluation of the Kundasang Ground Movement based on Geological, Geotechnical Investigations and Stability Modelling

Abstract

Kundasang is located in a geohazard zone that consists of two active major regional faults and weak geomaterials with highly weathered, jointed and fractured rock. The existence of active faults are considered as one of the factors which influence the occurrence of large ground movement in the Kundasang area. Kg Lembah Permai which is located adjacent to the Kundasang town is one of the critical affected areas by progressively ground movement that had caused significant destruction to the permanent structures and infrastructures that lead to economic loss to the government and residents, respectively. This paper describes past and new data, and also the outcomes that have been integrated to redefine and update the ground instability mechanism in Kg Lembah Permai. Two new approaches of mapping have been applied. The first is remote mapping which involved detection and interpretation of local faults using Digital Terrain Model (DTM) derived from Lidar image. The second is on-site mapping of geodynamic features in the field using 3D approach. Results showed that most of the destruction exhibited towards +Y and -Z direction which represent the movement towards northeast and vertical downward respectively. From landslide modelling, the rate of displacement, geometry of the sliding surface and the current stability condition of the landslide can be quantified. It is expected that with detailed and comprehensive knowledge, a suitable design of geotechnical solution at difficult ground can be conducted accurately and objectively which eventually could promote sustainable development and enhancing public safety in the Kundasang area.

Landslide susceptibility assessment in Sabah, Malaysia: A bivariate frequency ratio approach

“…Lineaments indicate underlying structural features, such as faults or joint fractures, displaying linear lines on the topography's surface (Murasingh and Jha, 2013;Prabu and Rajagopalan, 2013). These features may exhibit displacement near fault zones, significantly impacting the slope stability of the area.…”

“…The increase in tourism activities (Simon et al, 2014;Tating et al, 2015;Roslee et al, 2017) has led to rapid land use development since 1980 (Komoo and Lim, 2003), Thus development includes slope cutting for road construction and buildings, deforestation, and agricultural activities to promote fresh local crops. For example, several roads near the Tamparuli to Ranau area in Kundasang have been reported to experience creeping land movement following extensive development activities in recent years (Komoo and Lim, 2003;Liew and Gue, 2001;Mohamad et al, 2018;Omar et al, 2020). Moreover, the settlement area has been established within a moderately to highly prone area to landslide events, debris flow and active soil erosion, resulting in mass movements.…”