Document Type : Original Research
Department of Geology, Islamic Azad University- Lahijan branch, Lahijan, Iran
A mass wasting movement occurred along Chalus- Marzanabad freeway in March 2014 in Iran on which the most parts of the moved masses include soils with rock fragments. Province under construction freeway No. 3 is the main route from the capital city of Tehran to the Chalus city. The study area is located at the mileages between 5K and 6K along the freeway. Slope failures which triggered by earthquake activities and heavy rainfalls occur frequently. This paper is based on theoretical aspects and structural geology data for evaluation of the potential slope sliding behavior. The methodology is based on preparing topographic and geologic maps, measuring of layering and joints, preparing structural cross sections and rock mass rating of rock masses. According to RMR rating, Cohesion factor and friction angle of rock masses have been determined and used for analysis of mass wasting movements. This study showed an irrelevant relationship between the slippage behavior of the slopes and the stratum materials in the area. In this area, Infiltration of water into the shear zone of faults, swelling of the marlstone layers and the formation of flow in the clay bed cover has been the main cause of mass movements.