RNLI Wells-next-the-Sea

Soils Limited were commissioned to undertake a ground investigation by the RNLI for a proposed new lifeboat station at Wells-next-the-Sea, on the Norfolk Coast.

Client: RNLI | Marbas (Structural Engineer) | Studio Four Architects Ltd

Site Investigation: £15,000

The ground investigation was to supply the client and their designers with information regarding ground conditions, to assist in preparing a foundation scheme for development that was appropriate to the settings present on the site. The investigation was to be made by means of in-situ testing and geotechnical laboratory testing undertaken on soil samples taken from the trial holes.

The site investigation comprised:

– 2no. 30m deep cable percussive boreholes;

6no. CPTu probes to depths of up to 15m bgl; and

– 10no. TRL DCP in-situ CBR tests.

Ground conditions comprised Reclaimed Tidal Deposits recorded to depths of 13.00 and 12.50m bgl, overlying white chalk, noted to the full depth of the investigation at 30.45m bgl.

A series of in-situ and laboratory tests were undertaken to inform pile and pavement design for the proposed structure including: SPTs; CPTu probes; CBR probes; Atterberg test; PSD and SMC analysis; and sulphate and chloride tests.

Recommendations were made for pile design, including preliminary working loads and concrete classification in respect of sea waters (chloride) and sulphates. Advice on pavement design was also provided.