Subsurface Imaging
Electrical Resistivity Tomography (ERT)
2D and 3D resistivity imaging of complex subsurface conditions.
Overview
Electrical Resistivity Tomography is a powerful geophysical method that images the subsurface by measuring how electrical current flows through the ground. RIIM's ERT surveys produce detailed 2D and 3D resistivity cross-sections that reveal geological layering, groundwater, contamination plumes, voids, and buried structures with exceptional spatial resolution.
How It Works
An array of electrodes is deployed along a survey line or grid. Current is injected between pairs of electrodes and the resulting voltage is measured at other electrode pairs. This process is repeated for many electrode combinations to build a comprehensive dataset. The data is then inverted using specialist software to produce a 2D or 3D resistivity model of the subsurface.
Applications
- Pre-construction utility detection and conflict mapping
- Concrete scanning for rebar, post-tension cables, and voids
- Road and pavement layer thickness assessment
- Void and sinkhole detection beneath structures
- Archaeological and forensic subsurface investigation
- Oil and gas facility utility verification
- Live utility tracing in congested urban corridors
- Gas main and water main route verification
- Power cable and telecoms duct tracing
- Depth profiling of metallic utilities
- Verification of as-built utility records
- Pre-excavation safety surveys
- BIM Level 2 / Level 3 utility integration
- Clash detection for new infrastructure design
- Asset management database population
- 12D model creation for road and rail projects
- GIS utility layer creation and maintenance
- As-built utility record verification and update
- Offshore pipeline and cable route surveys
- Port and harbour development site investigations
- Seabed obstruction and wreck detection
- Dredging volume and pre/post-dredge surveys
- Subsea utility detection and mapping
- Environmental baseline seabed surveys
- Road and pavement void detection beneath carriageways
- Building foundation cavity assessment
- Karst and dissolution feature mapping
- Abandoned mine and tunnel detection
- Sinkhole risk assessment for development sites
- Pre-construction geohazard screening
- Void and cavity detection at depth
- Geological structure and fault mapping
- Salt dome and evaporite dissolution detection
- Buried valley and palaeochannel identification
- Mineral exploration and resource assessment
- Infrastructure site geohazard screening
- Seismic site classification (Vs30) for building codes
- Soil stiffness profiling for foundation design
- Liquefaction potential assessment
- Bedrock depth and rippability assessment
- Pavement and embankment condition assessment
- Geotechnical site characterisation
- Topographic survey and digital terrain modelling
- Construction progress monitoring and volumetrics
- Corridor mapping for pipelines, roads, and power lines
- Stockpile volume calculation
- Coastal and environmental change monitoring
- Infrastructure inspection and condition assessment
- Groundwater exploration and aquifer mapping
- Contamination plume delineation and monitoring
- Void, cavity, and karst feature detection
- Geological mapping and stratigraphic profiling
- Landfill and waste body characterisation
- Slope stability and embankment assessment
Deliverables
- Georeferenced utility plan drawings (AutoCAD / GIS)
- Depth profiles and radargram data files
- PAS-128 / ASCE 38-22 compliant survey reports
- 3D point cloud utility models (on request)
- BIM-ready IFC / DWG utility layers
- Georeferenced utility route drawings
- Depth and signal strength logs
- Combined GPR + EPL integrated utility plans
- PAS-128 / ASCE 38-22 compliant survey reports
- 2D utility plans in AutoCAD DWG / DXF
- 3D utility models in IFC / Revit / Navisworks
- 12D model files for civil design integration
- GIS shapefiles and geodatabases
- Utility conflict reports and clash matrices
- Bathymetric charts and digital elevation models
- Sub-bottom profile sections and interpretations
- Side-scan sonar mosaics and seabed classification
- Magnetic anomaly maps
- Integrated marine geophysics reports
- Cavity risk maps and anomaly location plans
- GPR radargrams and ERT resistivity sections
- Interpreted geophysical cross-sections
- Geohazard assessment report with risk classification
- Remediation recommendations
- Bouguer anomaly maps and gravity profiles
- 2D / 2.5D density models
- Geological interpretation maps
- Integrated geophysical interpretation report
- Recommendations for follow-up investigation
- 1D Vs profiles and 2D Vs cross-sections
- Vs30 values and seismic site class designation
- Dispersion curves and inversion models
- Geotechnical interpretation report
- Liquefaction susceptibility assessment (on request)
- High-resolution orthomosaic imagery
- Digital Surface Model (DSM) and Digital Terrain Model (DTM)
- Dense point cloud (LAS / LAZ format)
- 3D mesh models and textured surfaces
- Contour plans and volumetric reports
- 2D resistivity inversion sections
- 3D resistivity volume models (on request)
- Geological and hydrogeological interpretation
- Time-lapse ERT monitoring results (on request)
- Integrated geophysical investigation report
Common Questions