| Abstrakt: |
Malaysia is located in a tropical region and receives high rainfall intensity, especially during the monsoon season, which is often associated with landslide disasters. This study conducted a geotechnical investigation to examine the causative factors of a landslide incident on 18 September 2021 at Kemensah Heights, Hulu Kelang, Selangor, Malaysia. The landslide was triggered after three days of rainfall and shifted approximately 2536 m² of land, affecting three bungalows and 19 double-story houses located at the top and toe of the slope. The investigation used a combination of a Terrestrial Laser Scanner (TLS) Survey, a Public Work Department Probe Test also known as the JKR Probe Test, laboratory testing, and numerical modeling to analyze the landslide. Soil samples were collected to test grain size distribution, Atterberg limits, permeability, soil density, consolidated-undrained (CU) tri-axial strength, and soil density. The residual soils comprised sand (42%), silt (28%), clay (16%), and gravel (14%), classifying it as ‘silty sand’. The average permeability is 5.96 x 10-³ mm/s, indicating medium permeability. The slope angle measured using TLS and a geological compass ranged from 30° to 35°. The cohesion and internal friction angle of the soil is 11.3 kPa and 29°, which are less than the slope angle, indicating that the slope is susceptible to landslides. Numerical simulation analysis, using Plaxis 3D and Slope/W, was carried out to determine the factor of safety (FOS). This study concludes that the triggering factors causing the landslide were not only limited to the antecedent rainfall but were also due to excessive imposed load and the characteristics of the residual soil. [ABSTRACT FROM AUTHOR] |
