Development and formation mechanism of landslides along Changdu section of Lancang River

The most serious geo-hazards always occur in mountainous areas and plateaus in China, and a series of serious geo-hazards have occurred along the major rivers in eastern Tibet Plateau. Based on the previous research of InSAR remote sensing interpretation, through detailed field investigation, 75 landslides were determined along the Changdu section of Lancang River. Based on the analysis of the development characteristics and main influencing factors of landslides in detail, the formation mechanism of 6 types of typical landslides was summarized. The result shows that among the landslides along the Lancang River, the creep landslide in the accumulation layer is the most developed, and the river-cut slope caused by the rise and fall of the water level is the main influencing factor of the soil landslides along the river.High-location landslides near the river often slip directly into the valley, showing the high location but not remote characteristics. The two most developed types of slope structures in rock landslides are reverse and dip slopes, which are directly related to the bedding developed in the weak rock mass of sand and mudstone and the main joints perpendicular to the bedding. More than 85% landslides occur in the soft-little soft sedimentary rock association, indicating that the rock strength affects the development of landslides to a certain extent. The strong weathering zone on the surface of the slope and the accumulation body of the ancient landslide provide the material foundation for the landslides in accumulation layer, and these landslides are mostly characterized by creep sliding and multi-stage sliding. The Kagong-Yanjing active fault controls the spatial distribution of landslides. The faults control the landslide boundary and the fracture zone directly becomes the slide body. The results can provide reference and support for slope hazard management during the railway construction.