DIMENSION REAL TIME IMAGES OF RAINFALL INFILTRATION INTO UNSATURATED SOIL SLOPE

Abstract

Failure of soil slope is mainly due to infiltration of rainfall. The complexity of rainwater path
infiltrate soil slope can be predicted using commercial software, and volumetric moisture content at the
infiltrated slope area can be measured by Time-Domain-Reflectometry (TDR). Prediction of rainwater path is
based on parameters obtained by laboratory works, and volumetric water content using TDR can only
available at the point of insertion. In this research, an innovative method called Electrical Capacitance
Volume Tomography (ECVT) was used in geotechnical engineering application in determining the real-time
imaging of rainwater infiltration into unsaturated soil slope. This method also achieves permittivity value
through the experiments and converted to volumetric water content using equation. A soil sample obtained
from slope failure around National Defense University of Malaysia (NDUM) campus during monsoon season
was used in the research. The results revealed real-time 3 dimensions (3-D) images of rainwater infiltrated
into soil slope were produced through image reconstruction method of ECVT. Volumetric water content was
also achieved using permittivity value attained by ECVT result. Images which permittivity indicated the
infiltration of rainwater through soil slope were clearly shown in the results. This innovative technology is
expected to improve the understanding of soil slope behavior especially in for rainfall infiltration that relates
to soil stability.