Vol18 No.10: 2580-2596
【Title】Failure analysis on a heavy rainfall-induced landslide in Huay Khab Mountain in Northern Thailand
【Author】Veerayut KOMOLVILAS1; Weeradetch TANAPALUNGKORN1; Panon LATCHAROTE2*; Suched LIKITLERSUANG1
【Addresses】1 Centre of Excellence in Geotechnical and Geoenvironmental Engineering, Department of Civil Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand; 2 Department of Civil and Environmental Engineering, Faculty of Engineering, Mahidol University, Nakhon Pathom 73170, Thailand.
【Corresponding author】Panon LATCHAROTE
【Citation】Komolvilas V, TanapalungkornW, LatcharoteP, LikitlersuangS (2021) Failure analysis on a heavy rainfall-induced landslide in Huay Khab Mountain in Northern Thailand. Journal of Mountain Science 18(10). https://doi.org/10.1007/s11629-021-6720-8
【Abstract】On 28th July 2018, a massive landslide occurred in a mountainous area in Northern Thailand. The landslide after ten days of heavy rainfall generated the movement of uphill mountain soil into the populated village. This study presents a comprehensive failure analysis of local rainfall-induced landslides based on topographical and geological information. Rainfall measurement data were gathered from two rainfall stations close to the study area. The rainfall records show that the total monthly rainfalls in 2018 were significantly higher than the average monthly rainfalls over the past decade. Site investigation started with an unmanned aerial photogrammetric surveyto generate a digital elevation model. Then, dynamic probing test, microtremor survey, and electrical resistivity survey were carried out along undisturbed soils beside the failed slope to evaluate the thickness of the soft soil cover on top of the rock basement. During thesite survey, residual soil samples were collected to determine engineering properties in the laboratory. Finally, a slope stability analysis was performed to assess the landslide hazard based on the results of aerial photogrammetric survey, field exploration, and laboratory tests. The slope stability analysis and rainfall records revealed that the Huay Khab landslide was mainly caused by an increase in the water content of residual soils due to the prolonged rainfall which led to a sharp decrease in the shear strength. This leads to the conclusion that the proposed landslide investigation program could be used to assess the potential of landslide failure due to prolonged rainfall on a local scale.
【Keywords】Rainfall-induced landslide; Field exploration; Digital Elevation Model; Slope stability analysis; Northern Thailand