Substruck Ltd. was employed by a private client to complete dynamic probing on a green field site which was bounded by a stream and close to the estuary of the River Slaney. The works were completed as part of a ground investigation strategy completed by the project design team; BS5930:2015 would identify dynamic probing as phase 2-3 completed after a desk study / field reconnaissance, etc.
Four nr dynamic probes were completed at each corner of the property. The probes closest to the stream revealed very poor soils with the hammer falling under self weight for some parts until refusal was met at about six metres. The probes were wet on extraction and revealed a sandy SILT. Such values represent negligible bearing capacities and cannot be relied upon for a standard approach to foundation construction. Homebond recommend great care in the design on such soils. The probes furthest from the stream revealed improved resistance but were still wet on extraction.
The results showed a clear and simple profile of the soil conditions which were to be expected due to the location of the site. In this situation, a piled foundation is the most appropriate solution to foundation design as a deep trench fill would require a formation level of four metres and a raft foundation would pose a high risk of tilt.
A report was completed and forwarded to the project team for consideration.