The investigation covered National Route R56, Section 5, between kilometre 30.00 and kilometre 31.80. Its purpose was to establish the subsurface geological and material conditions along the affected section and provide geotechnical information to support the design of suitable erosion-stabilisation measures.
The work included setting out the investigation positions, rotary core drilling and the recovery of representative subsurface samples. The samples were securely transported for laboratory testing, with the two-month investigation completed during 2024.