Appendix D Geotech Site stability · MCU18/0013

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                                                                            Job No. 304-2014



The Bligh Tanner drawings referenced above, show that the site formation for the revised
building platform will require the construction of anchored, steel sheetpile retaining walls for
the temporary works. These temporary walls would then be followed by the construction of
reinforced concrete walls on the inside of the sheetpiles, and propped by the floor slabs.
In order to maintain the site stability, both the temporary and permanent retaining walls must
be designed to properly cater for the loads that could be applied to the wall. These include
appropriately selected soil lateral load (i.e. taking full account of the soil properties and
backslope angle), correct live load above the wall, as well as possible transient earthquake
and groundwater loads. It is considered that the surcharge loads shown in the notes to Drg.
No. 2004.052/A - item SP6, would adequately allow for these.
We are satisfied that if these retaining walls are designed, with these loads properly defined
and considered, detailed and constructed with appropriate good building practices, and the
site properly managed in the long-term, then current stability can be maintained, if not
improved.
That opinion notwithstanding, the certification of the ongoing stability of this site during and
after construction of this development is wholly dependent on the proper design of the
temporary and permanent retaining walls proposed for the site formation. Therefore such
certification must rest with the designers of these elements, who should be RPEQ with
appropriate experience in the design of retaining walls for sand excavations. We also note
that the final retaining wall design is to be subject to review by Soil Surveys Engineering Pty
Limited.


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We trust this information is satisfactory for your current needs, however, should you require
additional details or discussion, please do not hesitate to contact the undersigned at our
Sunshine Coast Office.


Yours faithfully,




STEPHEN GAMBLE (RPEQ 6644)

for and on behalf of
SOIL SURVEYS ENGINEERING PTY LIMITED




                                              SOIL SURVEYS ENGINEERING PTY LIMITED