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

October 2007                                     -2-                         077682076(AB)


As shown in Figure No. 1, which includes contours at 0.5 m intervals, the ground surface
generally slopes down towards the west to south-west at gradients of up to 5º (9%). Steeper
man-made slopes occur around features such as the golf tees and a lake adjacent to the
western boundary (where the eastern bank slopes at approximately 20º). Ground surface
elevations range from approximately RL 9 m AHD along the eastern boundary, down to
RL 1.5 m AHD in the low-lying south-western corner (area of proposed golf tees). The water
level in the lake on the western boundary was at RL 0.54 m AHD at the time of the survey.

A large part of the subject site is covered by a palm plantation, where rows of palm trees are
separated by areas of short grass. There are some stands of dense native vegetation, with
melaleuca observed in the low-lying south-western corner. The existing 18th fairway traverses
the south-western corner and underground services (power and sewerage pressure main)
traverse the southern part of the site.

3.0      METHOD OF INVESTIGATION

3.1      Preliminary Assessment

To assist with planning the level of detail required for this investigation a preliminary site
assessment was conducted, comprising:

•     a desktop study; and

•     a walk-over survey on 25 September 2007.

The desktop assessment comprised a review of available published reports and plans on
geology and ASS distribution. The findings from this preliminary assessment are presented in
Section 4.1.

3.2      Field Work

The fieldwork was planned in order to enable a preliminary assessment of geotechnical and
ASS matters for the proposed development. It should be noted that the ASS investigation
does not fully comply with the number of boreholes required by State Guidelines (Ref.
Section 5.2).

A total of eight boreholes (designated BH1 to BH8) were drilled across the site using a 4WD-
mounted flight auger rig. Six boreholes (BH1 to BH4, BH6 & BH7) were drilled to 3 m
depth, mainly across the proposed residential development area, whilst boreholes BH5 and
BH8 were extended to 6 m.

Dynamic cone penetrometer (DCP) testing was conducted adjacent to each borehole. One
undisturbed (U50) tube sample was recovered from 1.5 m to 1.75 m depth in borehole BH8
and was tested by pocket penetrometer (PP).




                                     Golder Associates