Effects of compaction on the erodibility of a residual soil of gneiss

Marcelo Heidemann,Bruna Sell,P Nierwinski Helena,Paulo Vinícius Da Silva,T.M.P De Campos,F.A.M Marinho,G.F.N Gitirana,M.M.A Mascarenha

doi:10.1051/matecconf/202133701013

Abstract

This work aims to verify the effects of the natural structure of a residual soil on its erodibility and the potential, employing compaction, to restore the erosion resistance. It is a residual soil of gneiss that occurs in the state of Santa Catarina, Southern Brazil. Infrastructure earthworks expose this material to the action of water, which can develop severe erosive features. The erodibility evaluation was made using the MCT methodology based on infiltrability and modified loss of mass by immersion tests. These tests were conducted in undisturbed specimens at natural moisture content and in compacted specimens at optimum moisture content. Such tests were also carried out in specimens air-dried for 24, 48, and 96 hours. This soil is inherently erosive, but the natural macrostructure makes it even more susceptible to erosion. Even compaction under modified energy is not able to recover the erodibility resistance. Drying slightly reduces the soil’s erosive potential when compacted, regardless of the compaction energy, but clearly increases the erosive potential of undisturbed soil.

Highlights

Erosion consists of processes by which materials from the earth's crust are removed and transported from one point to another to be deposited there
As there is no percolation of fluid in the field that has an effect similar to that of the deflocculating solution, it is debatable the establishment of parameters of erodibility derived from textural features for residual soils, especially those composed of fine particles
The undisturbed soil presents erodibility parameter "E" lower than those measured in compacted soil for all the moisture conditions considered

Summary

Introduction

Erosion consists of processes by which materials from the earth's crust are removed and transported from one point to another to be deposited there. When erosion is caused by water, it is called hydric erosion (Bastos 1999 [1]). This process can be greatly accelerated through anthropic action. This is basically due to changes in topography, which promotes an increase in energy and the concentration of water flow and exposes soils to water action. Nogami & Villibor (1995) [7] describe specific erodibility as the soil’s intrinsic resistance to detaching particles under the dynamic action of surface flow and raindrops

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