Spatial engineering geological and geotechnical modelling of embankment with RNK-method and stability analyses of waste water treatment facility (UPOV) in Vukovar

The RNK-method, or the Reference Level of Correlation method (RLC-method), represents a procedure for spatial engineering geological and geotechnical modelling, . The engineering geological (geotechnical) correlation column can be established in zones of limited extent (so- metimes occupying tens of km2) using one or several characteristic layers, one of which is selected as the reference layer. In the established correlation column, a soil liquid limit and plasticity index appear as useful indicators of the peak, fully softened and residual friction angle for coherent soils and soft rock formations. As a rule, maximum plasticity index and liquid limit values correspond to the minimum values of such friction angles. It offers the opportunity for correct spatial engineering geological (geotechnical) modelling with differrentiation of minimum shear strength zones (the weakest link in the "geotechnical chain of shear strength"), zones of different hydraulic conductivities, and zones of various degrees of natural compaction. The RNK method was tested on many landslides in Croatia, and in this paper the results obtained by its application on the potentially unstable area of waste water treatment facility (UPOV) in Vukovar are shown. This project and its location is of special interest due to presence of loess soils, vicinity of the river, relatively high seismic activity and warning examples of instability.