Construction and operation of transport infrastructure in the mountainous areas is an extremely important task. The complex structural-tectonic conditions with highly broken relief contribute to the development of modern landslide processes. Unexpected landslide activity carries a significant threat to both the road and transport infrastructure, as well as the life and health of people who use it. There are now known many different methods for protection of transport infrastructure by landslides, but the classic methods are not sufficiently effective to ensure reliable work of roads in mountainous areas and the considerable material costs involved are not justified. The reason for this is often the heterogeneity of a soil in composition and properties. A solution to this problem is to use suspension grouting to stabilize the landslide body. It was found that the injection of cement slurries with high water-cement ratio is only possible in weathered mudstone with cracks width> 10 mm, with injection pressure less than 6 atm. In this case, there is a uniform filling of cracks at a distance of 1, 5-2,0 meters from the injector. When the injection pressure increase occurs the hydraulic fracturing with the output hydraulic cement slurry to the surface. Processing of dense unweathered mudstone by suspension of colloidal silica with a concentration of 29% is possible to obtain a solid array with high strength characteristics that do not change even after 10 cycles of soaking/drying.
