Research On The Formation Mechanism And Stability Of The Shi'ezi Landslide

Longnan area, G212 passing by, has complicated and unsual geological environment and is one of place where landslide is most seriously growing. However, the degree of the landslide research is not deep enough due to the restraint of various factors and can not meet the demand of the high-ranked express highway construction. In this condition it is necessary to make a landslide special study in this area.The thesis is supported by western traffic science & technology item which is Highway construction technique research of the landslide and debris flow of National highway 212 in Longnan area. Here Shi'ezi landslide is a research objective. Based on the former datum, field reconnaissance and mapping, geophysical testing ,analyzing in the room, the geological background of the landslide has been greatly predominated. Formation Mechanism of the landslide has been discussed through using geological history analysis method. The whole history movement process has been basically reappeared, what's more, the stability of the landslide has also been valued by geological history genetic analysis, limiting equilibrium method and numerical analysis.Shi'ezi landslide is a huge landslide group controlled by fault zone. The feature of its shape is unusually complicated;and its cracks and platforms demonstrates this landslide is in youth-prime of its life;the geophysical prospecting materials shows this sliding surface of landslide has the cloverleaf feature in the different deep place. Formation mechanism of the landslide is very intricated, therefore Formation Mechanism of every sub-landslide has the characteristic of itself, forming condition and promoting elements are distinct and the mode of evolvement mechanism owns multiformity. Geological history analysis method shows that many section of landslide has the tend of moving, and Ks obtained by limiting equilibrium method and FLAC3D is smaller than 1.0, consequently landslide is still in the active stage recently.Finally, the corresponding the landslide treatments and measures have been advanced on the basis of the characteristic of landslide, formation mechanism and the result of stability comment, which provide the scientific proof for G212 passing this complicated region. At the same time, it may provide the reference of landslide prevention in the mountainous area for the highway building.