Appendix 5. Geotechnical Engineering Report [As Published] · 132007.2399

October 2007                                  - 17 -                          077682076(AB)


      continued exposure, as this may result in excessive drying followed by moisture re-
      adjustment (with associated expansive movements) when areas are overlaid by
      pavements or slabs.

Laboratory testing indicates that the site soils have Emerson class numbers of 6 to 8, which
indicates that the soils tested are non-dispersive. Normal best practice erosion and sediment
control will be required during construction.

6.2      Residential (Building) Development

6.2.1   Earthworks

Earthworks for residential development should be carried out in accordance with the
recommendations provided in Section 6.1.

6.2.2    Site Classification & Footings

Based upon the subsurface conditions encountered in the boreholes, without any additional
cutting or filling, we anticipate site classifications are likely to be ‘S’ in accordance with
AS2870-1996 “Residential Slabs and Footings”. For the majority of the residential
development area. The final site classification will depend on the type and compaction of any
new fill together with the potential reactivity of the natural soil profile.

Increased site classifications (eg. ‘M’, ‘H’ or ‘P’) may be required, and/or support on deeper
piled footings, for any buildings constructed above soft clay areas.

In general, residential footings should generally penetrate through any uncontrolled fill or
unsuitable natural soils and found at least 100 mm into medium dense ( or denser) natural
sand. Conventional strip, pad or beam footings so founded could be designed using an
allowable bearing pressure of 100 kPa.

It should be noted that individual site investigations (‘soil tests’) will be required prior to
building for every allotment.

6.2.3    Drainage

Drainage for individual residential allotments should comply with the recommendations in
Section 6.1.4, where applicable.

6.3      Further Investigation

Based upon the results of this preliminary investigation, it is our opinion that the proposed
residential development is feasible, from a geotechnical viewpoint, by incorporating
conventional geotechnical measures (possibly including preloading fills and piling buildings).




                                     Golder Associates