Abstract
Mapping the subsurface in slope stability analysis of disposal areas is difficult, especially the disposal layering materials that are assumed to be homogeneous instead of their real conditions. Moreover, the hoarding activities on high slope form layers based on the nature of the rock mechanics with large materials or boulders rolling down to the toe of the slope, while small ones are held at the top. Each layer formed, however, has certain geotechnical characteristics. The aim of this study is to determine the profiling of disposal material using a geoelectrical method known as Wenner–Schlumberger configuration with a line length of 450 m and also to find the resistivity value for mine waste materials based on an empirical number, which is a number that is obtained from the result reading compared to the actual condition in the field. The study was conducted on an in-pit dump with an estimated height of 150 m and a thickness of 50 m, and the data obtained were processed using RES2DINV software. The results showed that the subsurface cross-section has three layers consisting of bedrock with a resistivity of 50–70 Ωm, contact zone with 30–50 Ωm, and disposal material layer with 1–30 Ωm, which can be used for the slope stability analysis. This concept is very helpful for the geotechnical analysis on high mine waste dumps or sloping basement zone. This study focuses on the resistivity value for waste dump materials, which has not been clearly mentioned in the previous studies.
Geotechnical profiling of a surface mine waste dump using 2D Wenner–Schlumberger configuration