Use of MASW and electrical resistivity in assessing a small earth dam in remote area

Abstract

Electrical Resistivity Tomography (ERT), Multichannel Analysis of Surface Wave (MASW) and Dynamic Cone Penetration (DCP) test were conducted to assess any anomalies in an earth dam. ERTs were recorded using AGI Supersting R1/IP equipment - a total of 28 electrodes, spaced at one meter, were used in the resistivity setup - and then analyzed with EarthImager 2D. The MASW testing was performed using 24 geophones at one-meter spacing using Geometrics' GEODE G24 seismograph; the recorded data were analyzed using Geopsy for 1D and SeisImager for 2D profiles of the shear wave velocity. DCP test was conducted on the crest at various locations. Findings showed that the embankment of the dam consisted of three layers up to 5.8 meters of depth investigation. ERT also showed the existence of an area with low resistivity, indicating the potential for internal seepage. The shear wave velocity and DCP confirmed the existence of three layers, which was consistent with the resistivity results.