Geotechnical Drilling in Kent

Kent’s Ground Conditions

Kent's geology is remarkably varied, reflecting its position at the edge of the London Basin and the Weald. The principal formations encountered during site investigations across the county include:

• Chalk — the dominant bedrock across North Kent and the North Downs, ranging from weathered and frost-shattered near the surface to intact rock at depth. Chalk presents specific challenges including solution features and variable strength
• Thanet Sand — found beneath the chalk in parts of East Kent, a dense, fine-grained sand formation that provides good bearing capacity but can present groundwater challenges
• Lambeth Group — encountered across North and West Kent, comprising variable clays, sands, and gravels that can change rapidly over short distances
• London Clay — present across North Kent, a stiff, fissured clay formation that is generally well-suited to foundation design
• Weald Clay — the dominant formation across the Low Weald in South and West Kent, a stiff clay that can be subject to shrink-swell behaviour
• Alluvium — soft deposits found along the Medway, Stour, and Darent river valleys and the North Kent marshes, often requiring specialist foundation solutions
• Head deposits and River Terrace Gravels — widespread superficial deposits that can vary significantly in composition and engineering properties

Our long experience working across Kent means we understand how these formations behave during drilling and can advise clients and consultants on the most appropriate investigation strategy for their site.