ListersGeo offers Electrical Resistivity Imaging to assist Clients in developing effective ground stabilisation strategies in areas affected by ground dissolution. We routinely use the technique to plan and target our Phase 2 intrusive drilling programmes which allows us to avoid unnecessary drilling and minimise associated costs.
Electrical Resistivity Imaging (ERI)
As different soils and rocks exhibit different electrical properties, by applying a very small electrical charge to the ground, it is possible to measure and delineate material changes within the subsurface. We then use specialist mathematical processing and inversion software to construct these measurements into a detailed 2D image section through the ground.
In special situations, we have also used high-resolution ERI surveys to construct detailed 3D models of the geology beneath sites which form a powerful tool to both assess and communicate the complexity of the ground.
Using different equipment configurations, it is possible to accurately measure small changes in ground properties and infer likely engineering behaviour of soils to depths in excess of 25m below surface. We routinely achieve data acquisition rates of 300 linear meters per day and as such, ERI offers a high quality and extremely cost-effective way of rapidly assessing sub-surface conditions. Such an insight can offer a unique opportunity for Clients to actively manage construction costs, risks and associated liabilities without unnecessary disruption.
We approach every site differently depending upon the nature of the uncertainties, the anticipated geology and the working space available and have used ERI successfully on several high-profile projects to assess the following:
- Determination of depth and continuity of bedrock
- Identification of dissolution features (sinkholes)
- Locating buried structures
- Delineating the depth and lateral extent of infilled quarries and pits
- Slope stability assessments