Residential Development, Blaenllechau – Desk Study and Site Investigation
Introduction:
We were instructed by the Client to undertake a combined Desk Study and Exploratory Intrusive Ground Investigation, in order to provide design information for a proposed single residential development.
The development is a self build project and the outline design consisted of a single dwelling, garage and external areas all constructed into a steep mountain slope in South Wales. We became involved through an existing relationship with the designer and architect.
Details:
The site investigation commenced with a desk study including a review of the site history and environmental context alongside the anticipated geological model for the site, including a preliminary Coal Mining Risk Assessment. The works from the initial desk study and site investigation were required to take into account the relatively large dwelling proposed and the steep slope on which it is to be situated.
The walkover aspect of the Desk Study allowed the revised scoping of an investigation that utilised investigation techniques and equipment suited to the limited access nature of the site and was required to overcome some significant constraints, including working on slopes, heavy vegetation and limited access from the site entrance.
The investigation comprised hand held windowless sampling and shallow hand excavated trial pits which were aimed at providing geotechnical information and to allow sampling of soils as part of a contamination assessment.
It was also necessary to undertake a preliminary assessment of infiltration testing in order to determine if sustainable drainage could be considered. As access was not available to large plant, the use of Falling Head Infiltration Testing was implemented.
The findings of the investigation and assessment were used to aid detailed design of the development as part of a planning application and included consideration of contamination, foundation options tailored to the proposed construction and the potential for slope instability.