DETERMINANTS OF SLOPE STABILITY REDUCTION / DETERMINANTY ZNI ŽOVANIA STABILITY SVAHU

The formation or activation of landslide movements in Podtatranska kotlina is quite common, as it is flysh and volcanic area. There is a high incidence of sandstones in this area. The sandstones crumble and weather, and this is the reason why the subsoil becomes unstable. The rainfall is accumulated, and there is a danger of soil sliding down. There was located groundwater level in the central part of the slope (in the height of 30 cm), and in some parts, the water accumulation occurred in the depression places on the landslide body. There were created small landslide lakes, where the water was held during the year. The slope was soaked and the erosion started to increase. The slope with its instability has pushed the construction of road that leads underneath the heel of the slope. Neglected and improper construction in areas of slope landslides has become a relatively common phenomenon. Stabilization measures are often made up only when real problem occurs. An anthropogenic activity usually starts this problem. This refers to deforestation, grassing or deformation of slope stability in the heel by improper construction. The landslide was not the first one in the area. In 1898, there was the first landslide, but it was not as intensive as this one. Retaining wall was the only one stabilization measure which was built in that time. It also had a drainage outfall. However, during the summer months in 2010, the stabilization measure was disrupted and cracked. This occurrence started after the slope separation and by the foremost pressure on the given wing wall. During our measurements, we found out that in that area, there was a loss of plant cover, erosion accrued and soil physical properties changed. Our aim is to show the seriousness of the situation and propose appropriate stabilizing measures.