From:
Sent: 22 August 2024 09:22
@npt.gov.uk>; @npt.gov.uk>; @earthsciencepartnership.com>
Hi ,
We completed our trial pitting exercise last week at the bund on the former Godre’r Graig School site.
The bund composition varies and has been constructed out of variable abouts of tarmac, demolition arisings, topsoil/organic material including roots and cohesive material, such as clays. There are fragments of building stone etc that look oversized and may have been difficult to compact effectively.
We have concerns over the long-term stability of the bund.
We understand that the contractor has not undertaken the works in accordance with the Earthworks specification produced and has little records but it would be helpful if they could provide some information on the below main points to help our assessment and understanding.
- There is a grey cohesive (fine grained/clay) material within the bund, is this from site or imported – how was this material selected and compacted? Was the moisture content of the material monitored at placement?
- Was the demolition arisings crushed/processed to a specific grading/soil class? Or was this done on an adhoc/uncontrolled nature.
- Was the material placed in layers, if so how thick were they?
- Were parts of the bund complete first then moved along, or was the entire length of the bund donethen raised in layers?
- Was the excavator on site used to provide the compactive effort for the bund layers, if so, how manypasses/times was this used – or was other plant used?
- How was organic material, soils screened prior to placement in the bund? Can evidence be providedthat it was removed from site, skips/transfer tickets.
- Are there any proposals to control surface water run off from the former playground area into thebund? Has the aco drain in this area been protected. Are all the other drains crossing the site in working order?
If you would rather us contact them directly we can do so and would just need their contact details.
We’ve collected samples and will start geotechnical testing and will need to re runs some slope stability modelling based upon our findings.
@npt.gov.uk> Subject: Godre’r Graig Bund
