the research of unsaturated loess has an important meaning to the slope stability of loess region.The microscopic structure of loess is analyzed using SEM image and the stability of a typical loess landslide is evaluated using Janbu method.The study result shows that cementation is less on the big particles.With the increase of the depth
the overburden increa-ses.Soil mass has obvious extrusion deformation.The loess body in the natural state is stable
but the stability of the slope decreases with water content.The slope becomes unstable when the loess is saturated.With the rapid economic development
human water matter activity and extensively development of economic activities of engineering continually expand in the loess area.Human activities gradually become the main factors of landslide causing.