We were engaged to enable a residential development on 1ha greenfield site in Neath. A coal mining risk assessment suggested the presence of a shaft on site, and potential shallow mine workings.
While mine workings in the Graigola coal seam were con-firmed by drilling, geophysics and trial trenching at the recorded shaft location failed to identify its presence. To successfully confirm its absence, we designed a robust mine shaft investigation strategy whilst min-imising the potential detriment to the shallow ground conditions and the geotechnical design of the development. Recommendations for further risk mitigation were provided.
Phased intrusive mine shaft investigation using a range of techniques successfully zoned the potential mining hazards across the site allowing a design layout to be developed. This included the robust demonstration of the absence of a mine shaft suggested to be present based on Coal Authority records.
- Desk Study (including Coal Mining Risk Assessment);
- Site Walkover and Visual Assessment;
- Supervision and design of multi-phased trial pit, trial trench, rotary drilling and geophysical investigation;
- Cost effective mine shaft investigation design;
- Geo-environmental assessment and geotechnical design;
- Identification of shallow mine workings and assessment of subsidence risks;
- Preparation of site hazard maps to aid development design relative to the potential mining risks.