Integrated Multimodal Approach for 3D Subsurface Characterization: Leveraging Geophysical, Geotechnical Methods, and Cross-Plot Analysis

Summary This research focuses on a multimodal approach to 3D subsurface characterization, integrating geophysical, geotechnical, and UAV-based methods. UAV photogrammetry captures high-resolution topographic data, while Electrical Resistivity Tomography (ERT) and Seismic Refraction Tomography (SRT) provide complementary subsurface insights. Borehole investigations validate and refine the geophysical models, ensuring accurate representations of geological structures and material properties. The study was conducted in Sungai Jawi, Penang, Malaysia, characterized by granitic soils and varying weathering profiles. UAV data, georeferenced using RTK technology, was processed into detailed topographic models. Geophysical surveys employed advanced techniques like weight-drop-generated seismic waves and Wenner-Schlumberger array configurations for resistivity measurements. Borehole data added ground-truth precision, and RockWorks software integrated all datasets into a comprehensive 3D model. Cross-plot analysis correlated resistivity and seismic velocity data, enabling classification of subsurface materials. The resulting model supports applications like slope stability assessment and foundation design, addressing the limitations of individual methods. This research highlights the effectiveness of multimodal integration for accurate subsurface characterization and provides a framework for future advancements in geotechnical and geophysical engineering.