Dokumentowanie geologiczno-inżynierskie osuwisk w aspekcie głębokości występowania powierzchni poślizgu

When conducting geological and engineering research, the most common statement is information that the landslide is shallow and should not pose a threat to the designed objects. In the case of large, structural landslides, this approach may lead, with the wrong determination of the deepest slip surface, to the occurrence of a construction disaster as a result of improper execution of the protection structure. The article presents specific locations of landslides with deep displacements in inclinometric columns exemplified by landslides monitored as part of the SOPO project in Tarnawa Górna, Słotowa and Międzybrodzie Bialskie - Łazki. The documented slip surfaces are found at depths of 19-42 m. Such deep displacements indicate that large, landslides reach significant thicknesses and such data should be presented in a geological and engineering documentation. It is proposed to modify the regulation on the execution of the geological and engineering documentation by adding a point regarding the documentation of landslides. If such an area exists, special requirements must be met when conducting geological surveys.