Engineering geophysics has become a crucial tool in mining and engineering consulting, driven by the need for efficient, sustainable, and safe practices. This article explores innovations in engineering geophysics at SRK.
The field of engineering geophysics has transitioned from 1D models to 2D and 3D geophysical data models. This evolution has been driven by advancements in methods like multichannel analysis of surface waves (MASW), electrical resistivity imaging (ERI), gravity surveying, and ground-penetrating radar (GPR).
Seismic surveys, including MASW and seismic refraction, are crucial for civil construction projects. They quantify rippability, determining appropriate excavation equipment and methods, which significantly impacts schedules and costs. The shear wave velocity profile, particularly the VS30 and stiffness parameters, is essential for seismic hazard assessments of structures like tailings dams and rock dumps.
ERI is widely used to identify subsurface boundaries, but its effectiveness depends on the applied array, survey protocol, and data processing. Innovations such as the maximum directional gradient algorithm have improved the delineation of material boundaries. Work is underway to develop 3D bulk Rock Quality Designation and Rock Mass Rating products by combining ERI, MASW, and geotechnical data using machine learning methods.
Gravity surveys are primarily used in engineering studies to detect cavities. However, the small gravity anomalies in these studies require accurate terrain and density corrections. New algorithms based on the Hammer net method have been developed to address this challenge, incorporating multithreaded parallel processing for improved efficiency.
GPR is extensively used in railway substructure surveys to assess track substructures. New software and workflows have been developed to process GPR data more efficiently, reducing turnaround times by up to 80%. This innovation provides crucial parameters for assessing railway ballast and sub-ballast quality. There is potential for expanding the software for use in road evaluations.
Despite these advancements, challenges remain in engineering geophysics. Issues such as insufficient data points in gravity surveys, incorrect ERI survey arrays and inappropriate MASW survey layouts can lead to inaccurate interpretations and flawed engineering decisions. Adhering to best practices and employing appropriate methodologies are essential for ensuring accurate and reliable geophysical survey results.
The innovations in engineering geophysics, many of which are being developed by SRK, have significantly enhanced the industry’s ability to image and quantify subsurface features and conditions. By continuing to innovate while maintaining rigorous standards, the geophysical engineering field can further enhance its contributions, fostering greater trust and reliability in geophysical techniques.
