Integrated Geophysical and Mechanical Methods for Slope Stability Assessment in Weathered Sedimentary Rocks

Summary This study investigates slope stability in sedimentary rock formations influenced by weathering, with a focus on tropical climates like Malaysia. Weathering transforms rocks into residual soil, weakening structural integrity and complicating stability assessments. The research integrates Electrical Resistivity Tomography (ERT), Slake Durability, and Knocking Ball tests to evaluate subsurface conditions and rock properties comprehensively. ERT is a non-intrusive method offering detailed insights into geological structures and weak zones. The Slake Durability Test examines rock resistance to weathering through wetting-drying cycles, while the Knocking Ball Test measures the elastic modulus and stiffness of rocks. Conducted on the Kubang Pasu formation in Kedah, Malaysia, results reveal that higher resistivity values correlate with increased rock stiffness and weathering resistance, indicating less degraded materials. The study demonstrates a critical connection between subsurface resistivity, elastic modulus (Ekb), and Slake Durability Index (SDI). Resistivity profiling effectively identifies weak zones and material degradation, while mineralogical analysis reinforces links between resistivity, mechanical properties, and weathering states. These findings provide an integrated framework for slope stability assessment, with a potential for hazard mitigation and improving geotechnical practices. Future research could test this methodology in diverse geological settings to further refine slope stability assessments.