14169-001-Rev0 17 Webb Rd -Revised Draft · 132002.220527.1

                             17 WEBB ROAD, SUNSHINE BEACH
                             PROPOSED RESIDENCE



Executive Summary
This report details the results of a geotechnical investigation carried out for the proposed renovation to the
existing residence at 17 Webb Road, Sunshine Beach. The geotechnical investigation was undertaken by
Tectonic Geotechnical Pty Ltd (Tectonic) for Mr Murray Charlton. This report summarises the results of the
investigation and provides an assessment of slope stability, together with advice regarding earthworks,
foundations, retaining walls and drainage for construction.

The development will comprise renovations to the residence within the footprint of the existing house. Up to
about 1 m of cut / fill is anticipated. Construction will comprise a combination of masonry and light-weight
cladding walls.

The site investigation comprised drilling of three boreholes up to depths of 3.2 m below ground level (BGL) at
the front and rear of the existing residence. A soil sample obtained from the boreholes was forwarded to a
geotechnical testing laboratory for soil classification analysis.

Subsurface conditions encountered in the boreholes comprised loose to medium dense sands (fill and
natural soils) to about 0.5 m BGL, then medium dense natural sands grading to dense and very dense with
increasing depth. Groundwater was not encountered in the boreholes during the investigation.

The site classification for the (existing) natural soil profile is Class S (in accordance with AS2780). The
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building shall be supported on footings which penetrate at least 0.2 m into the natural medium dense sand
(about 0.5 m BGL), or may be supported by screw-in piles taken into the dense to very dense sands at about
2.5 m BGL.
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Considering the existing site conditions, and subject to the implementation of recommendations given within
this report, it is our opinion that there is a Low (L) Risk of global slope instability affecting the proposed
residence, with a factor of safety against slope instability of at least 1.5.
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26 February 2015
Report No. 14169-001-Rev0                              ii