Studying the Interaction Between Active Faults and Landslide Phenomenon: Case Study of Landslide in Latian, Northeast Tehran, Iran

In this article, the interaction between active faults and landslide phenomenon is studied. The case study concerns the landslide in the east of Latian Dam to the northeast of Tehran, the Capital of Iran. The methodology was based on geological studies, geomorphologic studies, the study of landslide phenomenon including its characteristics and its parameters, hydrogeology, geological engineering and the geotechnical studies. The results show that landslide is located in the crush and mylonitized zone of the Roodehen active fault. The geological formation includes the landslides of the Eocene tuffs, which have been severely crushed and pulverized by the Roodehen Fault’s actions, and for this reason, they show very weak geotechnical characteristics compared to the natural tuffs. The layering slope of the formation is according to the natural ground slope and facilitates their slips. According to the results, the main reason for landslide is the impact of the Roodehen active fault and the creation of crush and mylonitized zone in the Eocene tuffs, while the secondary parameters are the local geological structures, the unfavorable conditions of the groundwater and their inadequate drainage and the construction of a road along the ground layers. The existence of groundwater, the low impermeability of the landslide materials and the inadequate drainage are also under the influence of the fault. Moreover, based on the results of this research and the location of the considered landslide and a number of others along the Roodehen Fault, it became possible to study the fault’s activity from a seismotectonic point of view and to estimate the magnitude of such an eventuality by methods other than the conventional ones.