Abstract

• The most destructive landslides had happened in Hakha on 27th July 2015and fortunately, no one faced to death in this event. However, the huge size posed a great impact on vulnerability of the town infrastructure, housings and inhabitants. In order to support the local people and regional planners, landslide investigation was carried out to produce potential landslide hazard zonation map. This paper mainly aims to present which factors play the main role in failure mechanism in this study area. Three types of landslides had been recorded in this area and the phenomena of landslides were detail investigated especially landslides in Mt. Rung and Hakha environs. The occurrence of numerous cracks on the middle and bottom potion of the landslide slope caused the critical condition for the ability to sustain this area. Therefore, to analyze this hazardous condition, the engineering properties such as physical, mechanical properties and dispersive nature of landslide materials were analyzed. From the analysis of grain size distribution and Atterberg’s limit test results, those landslide materials are low plasticity Clayey SILT (ML)by the application of unified soil classification system(USCS). The several controlling factors of landslides were noted from the field investigation and laboratory analysis in which the most crucial factor of dispersive nature to accelerate landslide when it combines with intense rainfall had been verified in this paper.