ANALYSIS OF THE EVOLUTION AND RESURGENCE SLIDING ME-CHA-NISM OF LANDSLIDES IN THE EASTERN PART OF YONGSHAN COUNTY

Many low-angle dip bedding slopes distribute alongside Jinsha River, some of which have evolved into gently, stable macro-paleo-landslides. The existing city are just located in these gently paleo-landslides, which may also be planned to be extension areas. Therefore, it is important to study the evolution process and mechanism of landslide renewed, to prevent the paleo-landslides from renewing and being unstable. The article has analyzed the evolution process and mechanism of landslide renewed, taking the landslide in east side of Yongshan County as example. The evolution renewing processes have been divided into 4 phases:(1) superstratum cracked and dislocated due to interlayer squeezing and plastic flow of soft interlayer, (2) superstratum sliding fast, collapsing and partly disassembling to block the Jindi River, (3) landslide accumulation collapsing, densifying, creeping deformation, then intending to be stable, (4) part of sliding blocks renewing. Surface water seepage from atmospheric precipitation, daily used water is the main inducement for the landslide renewing; secondly, this landslide area meets seismic active period recently. This study provides a theoretical basis for the late comprehensive prevention and control of landslides in eastern side of Yongshan County, and provides experience and reference for the investigation and comprehensive prevention and control of similar renewing paleo-landslides. In the meantime, this study is valuable for the prevention and control of these similar paleo-landslides and urban planning alongside Jinsha River.