<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Field tests were carried out to estimate effective unsaturated soil hydraulic properties of layered residual soils in Rio de Janeiro, southeastern Brazil. Data of this type are important for understanding the initiation of rainstorm-induced soil landslides, which often occur in the state of Rio de Janeiro as well as other areas having similar geologic settings and climate conditions. Tests were carried out using a simplified field approach, referred to as the Monitored Infiltration Test, which requires only a tensiometer to measure pressure heads below the wetting front, triggered by flow from a Mariotte bottle which maintains a constant pressure at the top edge of the soil profile. The data can then be analyzed by numerical inversion using the HYDRUS-2D software package. The test is relatively fast since no steady-state flow conditions are needed, and versatile since the test can be carried out quickly on steep slopes with the help of a manual auger. Soil water retention and the unsaturated hydraulic conductivity functions were obtained for a range of young, mature and saprolitic residual soils. The effective hydraulic properties of the distinct residual soil layers can be quite large, reflecting a need to provide a careful analysis of field-scale hydraulic heterogeneity in geotechnical analyses.</p>
</abstract>

Field tests were carried out to estimate effective unsaturated soil hydraulic properties of layered residual soils in Rio de Janeiro, southeastern Brazil. Data of this type are important for understanding the initiation of rainstorm-induced soil landslides, which often occur in the state of Rio de Janeiro as well as other areas having similar geologic settings and climate conditions. Tests were carried out using a simplified field approach, referred to as the Monitored Infiltration Test, which requires only a tensiometer to measure pressure heads below the wetting front, triggered by flow from a Mariotte bottle which maintains a constant pressure at the top edge of the soil profile. The data can then be analyzed by numerical inversion using the HYDRUS-2D software package. The test is relatively fast since no steady-state flow conditions are needed, and versatile since the test can be carried out quickly on steep slopes with the help of a manual auger. Soil water retention and the unsaturated hydraulic conductivity functions were obtained for a range of young, mature and saprolitic residual soils. The effective hydraulic properties of the distinct residual soil layers can be quite large, reflecting a need to provide a careful analysis of field-scale hydraulic heterogeneity in geotechnical analyses.

Field-scale assessment of the unsaturated hydraulic properties of residual soils in southeastern Brazil

Department of Environmental and Civil Engineering

Pontifical Catholic University of Rio de Janeiro

Journal of Hydrology and Hydromechanics

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Field tests were carried out to estimate effective unsaturated soil hydraulic properties of layered residual soils in Rio de Janeiro, southeastern Brazil. Data...

Field-scale assessment of the unsaturated hydraulic properties of residual soils in southeastern Brazil

Published Online: May 19, 2022

Page range: 244 - 256

Received: Mar 29, 2022

Accepted: Apr 25, 2022

DOI: https://doi.org/10.2478/johh-2022-0013

Keywords
Residual soils, Unsaturated soil hydraulic properties, Field infiltration tests, HYDRUS-2D

© 2022 Ruan G.S. Gomes et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Field-scale assessment of the unsaturated hydraulic properties of residual soils in southeastern Brazil

Published Online: May 19, 2022

Page range: 244 - 256

Received: Mar 29, 2022

Accepted: Apr 25, 2022

DOI: https://doi.org/10.2478/johh-2022-0013

KeywordsResidual soils, Unsaturated soil hydraulic properties, Field infiltration tests, HYDRUS-2D

© 2022 Ruan G.S. Gomes et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
Residual soils, Unsaturated soil hydraulic properties, Field infiltration tests, HYDRUS-2D