In Bradford, geophysics addresses the variable ground conditions linked to the Millstone Grit, Coal Measures, and overlying glacial deposits. Our surveys provide critical subsurface data, directly informing foundation design and earthworks in line with BS 5930:2015+A1:2020 and Eurocode 7. For seismic site classification, we employ MASW / VS30 to determine shear wave velocity profiles, while HVSR microtremor survey defines natural resonance frequencies, essential for sites with complex superficial geology.
These investigations are vital for residential developments on sloping terrain, commercial builds on former industrial land, and infrastructure projects where voiding from historical mining is a risk. To resolve ground stability and foundation conditions, we complement seismic methods with electrical resistivity / VES, mapping depth to bedrock and detecting saturated zones or clay variations across the district.
Applied geophysics in geotechnics delivers subsurface information over large areas with low impact and reasonable cost, complementing point information from boreholes. Seismic, electrical and electromagnetic methods allow identification of stiffness contrasts, groundwater presence, bedrock depth and anomalies such as cavities or anthropic fills.
Seismic refraction and reflection, along with surface wave methods (MASW, ReMi), deliver P and S-wave velocity profiles of the subsurface, data directly applicable to site seismic classification per current codes and calculation of dynamic moduli for seismic response analysis.
Electrical resistivity tomography (ERT) and vertical electrical sounding (VES) identify resistivity variations associated with soil type, water content, contamination or rock presence. Ground penetrating radar (GPR) delivers high-resolution images of shallow subsurface, useful for buried utility location, pavement thicknesses and cavity detection.
Integration of geophysics with localized boreholes and laboratory tests allows construction of robust three-dimensional geological-geotechnical models. Their interpretation must be performed by specialists with local experience, considering the inherent limitations of each method and particular site conditions to avoid erroneous conclusions.