Geotechnical assessment for the construction of a four storey house (25,000Ft2), with a lower basement to accommodate a swimming pool and standalone two storey garage and apartment block on the side of a former Sandstone quarry in Lancashire. The Sandstone had been quarried leaving a Mudstone deposit that weathered significantly when exposed to the elements. Several attempts had been made to re-profile the quarry to allow the construction of a residential property.
Beech Consultants were commissioned to undertake the following works:
- An assessment of the stability of the re-profiled rock and original overburdened soils in the vicinity of the proposed house, already partway under construction.
- Rotary boreholes were used to investigate the thickness and intact strength of the Mudstone at the site.
- A strategy was then submitted, following consultations with the projects appointed structural engineers, for the regrading of over-steep embankments, re-profiling of the formation constructed within the Mudstone strata and changes to the design,
- Provision of a specification of the regrading and earthworks as an engineered formation to the proposed reinforced concrete foundation and retaining walls.