One-dimensional experimental study of rainfall infiltration into unsaturated soil

Abstract

This paper presents experimental results obtained from tests on unsaturated soil in one-dimensional columns simulating a rainfall infiltration process. Six columns composed of compacted Silty Sand were prepared to study the effects of the initial water content and rainfall intensity on the downward infiltration process. The advance of the water front was monitored using sensors to measure pore water pressure and volumetric water content installed at different locations along the height of the Silty Sand column. The test results show that the lag time, defined as the time difference from the beginning of the test to a sudden increase in the volumetric water content readings, was influenced by the soil initial water content and rainfall intensity; it is observed that the lag time is shorter at higher initial water contents and greater rainfall intensities. The results provide insights to understand the hydraulic behavior of unsaturated slopes and embankments exposed to rainfall infiltration. RESUMEN:En este artículo se presentan los resultados experimentales obtenidos a partir de ensayos en suelo parcialmente saturado en columnas unidimensionales, simulando un proceso de infiltración de lluvia. Se prepararon seis columnas de arena limosa compactada para estudiar los efectos del contenido inicial de agua y de la intensidad de la lluvia en el proceso de infiltración descendente. El avance del agua fue monitoreado usando sensores para medir la presión de poros y de contenido volumétrico de agua instalados a diferentes alturas de la columna de arena limosa. Los resultados de los ensayos muestran que el tiempo de retraso, definido como la diferencia de tiempo desde el inicio del ensayo hasta el aumento súbito en las lecturas del contenido volumétrico de agua, fue influenciado por el contenido inicial de agua en el suelo y la intensidad de la lluvia; se observa que el tiempo de retraso es más corto a mayores contenidos iniciales de agua y mayores intensidades de lluvia. Estos resultados proveen información para comprender el comportamiento hidráulico de taludes y terraplenes parcialmente saturados expuestos a la infiltración de lluvias.

Experimental Investigation of Water Infiltration Law in Loess with Black Locust (Robinia pseudoacacia) Roots

“…In this study, the soil column experiment was performed using a transparent cuboid model device. An interesting finding is that the wetting fronts migrated in a straight line in the cube model box containing loess at constant head height, which is consistent with the results using cylindrical model box under the same conditions [44,45]. This shows that the shape of the model box had no effect on the migration characteristics of wetting fronts.…”

Development of a Rainfall and Runoff Simulator for Performing Hydrological and Geotechnical Tests

“…Several studies have presented the development, calibration, and use of RSs for a wide range of purposes, such as agricultural research [17][18][19][20][21][22]; biomass studies [23,24]; infil-Sustainability 2021, 13, 3060. https://doi.org/10.3390/su13063060 https://www.mdpi.com/journal/sustainability Sustainability 2021, 13, 3060 2 of 22 tration analysis [14,15,25,26]; urban hydrology simulation, including permeable pavement performance [27], evaluation of processes of accumulation and transport of pollutants on pavements and roof surfaces [28][29][30][31][32]; and rainwater quality research. RSs are frequently used in geotechnical evaluations of soil loss and erosion [1,16,22,[33][34][35][36][37][38], slope stability [13,39,40] and infiltration, and percolation in unsaturated soils [12,14,15,41,42]. The performance of RSs must be evaluated considering various initial conditions, boundary conditions, simulated rainfall characteristics, and the scale factor (i.e., the evaluation of the specimen geometry and dimensions).…”

Numerical evaluation of laboratory apparatuses for the study of infiltration and runoff

“…Several authors have designed and evaluated different types of RA's for different fields of study: for agricultural research (Montebeller et al, 2001;Alves Sobrinho et al, 2008); for infiltration studies (Shao & Baumgartl, 2014;Rahardjo et al, 2016); for urban hydrology, in particular related to permeable pavements (Araújo et al, 2000;Silva, 2006;Castro, 2011); and for the study of quality of runoff water from pavements and roofs (Egodawatta, 2007;Egodawatta et al, 2007Egodawatta et al, , 2009Minguntanna, 2009), all using the RA developed by Herngren (2005). RA's are also used to evaluate soil erosion (Poesen et al, 1994;Römkens et al, 2002;Das Kunststoff-Zentrum, 2011;Zhang et al, 2014;Sadeghi et al, 2015;Wang and Lai, 2018;Liu et al, 2019), landslides and slope stability (Egeli & Pulat, 2011;Cecconi et al, 2015;Montrasio et al, 2016); and infiltration in unsaturated soils considering subsurface flow (Miyazaki, 2005;Montoya-Dominguez et al, 2017).…”