Evaluating Landslide Remediation Methods Used in the Carpathian Mountains, Poland

Abstract

ABSTRACT The aim of this study was to evaluate the results of landslide remediation in the Polish Carpathians. The research for safeguarding the roads and infrastructure was conducted in the years 2005–2018 in nine landslide areas. The interpretation of engineering geology conditions was complex due to the soil-rock nature of the flysch sediment. Movements were activated after heavy rainfalls. In two cases, triggers were connected with the undercutting of the slope or external loading. The research methods included mapping, drilling, index, oedometer, direct shear tests, ground-penetrating radar scanning, and numerical modeling. To date, 15–59 series of inclinometer and piezometer network readings in 30 locations have been taken. Three online stations have been delivering continuous, nearly real-time data since May 2010. Displacements before the remediation ranged from a few millimeters to several centimeters. The proposed remediation methods included piles, micropiles, anchors, retaining walls, and drainage systems. Six stabilization projects were prepared and checked using the limit equilibrium method and finite element method modeling. The research shows that in five landslide areas, the proposed remedial works were effective. Two other partial stabilization works limited the scope of the movements but did not eliminate the risk. At two locations, only temporary repairs were conducted. Proper identification of the landslide triggers and activity is standard for the recognition of counteraction possibilities and could lower stabilization costs. The selected methods delivered data for remedial decisions. However, effective remediation of an active Carpathian landslide is difficult. It requires individually calibrated investigations, representative monitoring, and careful design of stabilization.