Stabilization of Landslides Sliding Layer Using Electrokinetic Phenomena and Vacuum Treatment

Janusz Ukleja

doi:10.3390/geosciences10080284

Abstract

The article presents the efficiency of application of cohesive soil dewatering for increasing its resistance to shearing, which influences the mass stability of flysch rock. Studies of the typical soil constituting the contact layer initiating the sliding of existing Carpathian flysch landslides were conducted. This aspect was examined because the water content of this soil decides its ability to form a sliding surface of the landslide block soil. The soil was subjected to changes in water content by dewatering with different methods. The influence of dewatering by self-acting gravitational outflow was examined and was additionally aided by two selected methods: electrokinetic phenomena and vacuum treatment. The model study conducted demonstrates the influence of the abovementioned dewatering methods on increasing the strength parameter of the soil at the contact layer in which sliding surfaces can be created. The paper also demonstrates the degree to which the application of the vacuum and electrokinetic treatment caused by DC current voltage influences the draining, decrease of plasticity, and increase of soil shear stress resistance. The application conditions and increase in effectiveness due to the application of the studied methods were determined. The proposed methods allowed for the strengthening of slopes for two exemplary landslides which formed in the area of occurrence of the Carpathian flysch.

Highlights

Studies of issues related to the influence of electrokinetic phenomena have been carried out for the past century Horvitz 1939 [1]
This paper presents an original approach to analyze the critical part of a landslide, that is, the contact between two soil layers: (i) the static consolidated layer; (ii) the unconsolidated, wet, unstable layer
The results of this study demonstrated that the distribution of induced voltage and vacuum of the pores along the sample are constant at continuous current flow in the whole sample

Summary

Introduction

Studies of issues related to the influence of electrokinetic phenomena have been carried out for the past century Horvitz 1939 [1]. In 1949 [2] and 1961 [3], Casagrande described the practical application of the electrokinetic processes for clay soil. Studies conducted by Ukleja 1972 [4] and others show that this method is very effective for these kinds of soils. The idea of the electrokinetic treatment (ET) process (in relation to geotechnical issues) basically covers the following three phenomena: . Electroosmosis is based on the flow of ground water ions (diffusive and free) as a result of an electric field rising, caused by DC, in the direction from the anode to the cathode. Electroosmosis is the most important process for the successful dewatering of sediments. Electrophoresis depends on the displacement of negatively charged colloidal size particles of the soil environment from cathode to anode (anaphoresis) or of positively charged ones from anode to cathode (cataphoresis)

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