Compiled Reference Documents - OPW25/0053 (As Published)

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It is understood that the proposed retaining wall may comprise a cantilevered masonry block wall
supported on a strip footing. Alternatively, a concrete sleeper wall spanning between steel
‘soldier’ posts supported by concrete bored piles could also be considered.

The results of the stability analysis indicates that the minimum required factor of safety (FoS) of
1.5 for the proposed retaining walls can be achieved using an appropriately designed retaining
wall provided shear pile support is provided. Our analysis has assumed that the proposed
retaining wall would be supported on bored piers founding at 2.5 m depth at 1.6 m spacings with
each pile providing an unfactored shear force of 150 kN.

The outputs of the slope stability analyses are presented in Drawing 2 in Appendix B.


6. References

AS 4678. (2002). Earth-retaining structures. Standards Australia.




7. Limitations

Douglas Partners Pty Ltd (Douglas) has prepared this report for the proposed retaining wall at 10
Surfside Court, Sunshine Beach. This report is provided for the exclusive use of the Mort Family
Trust for this project only and for the purposes as described in the report. It should not be used
by or relied upon for other projects or purposes on the same or other site or by a third party. Any
party so relying upon this report beyond its exclusive use and purpose as stated above, and
without the express written consent of Douglas, does so entirely at its own risk and without
recourse to Douglas for any loss or damage. In preparing this report Douglas has necessarily
relied upon information provided by the client and/or their agents.

The results provided in the report are indicative of the subsurface conditions on the site only at
the specific sampling and/or testing locations, and then only to the depths investigated and at
the time the work was carried out. Subsurface conditions can change abruptly due to variable
geological processes and also as a result of human influences. Such changes may occur after
Douglas' field testing has been completed.

Douglas' advice is based upon the conditions encountered during this investigation. The
accuracy of the advice provided by Douglas in this report may be affected by undetected
variations in ground conditions across the site between and beyond the sampling and/or testing
locations. The advice may also be limited by budget constraints imposed by others or by site
accessibility.

The assessment of atypical safety hazards arising from this advice is restricted to the geotechnical
components set out in this report and based on known project conditions and stated design
advice and assumptions. While some recommendations for safe controls may be provided,
detailed ‘safety in design’ assessment is outside the current scope of this report and requires
additional project data and assessment.




Proposed Retaining Wall                                                            222438.01.R.001.Rev0
10 Surfside Court, Sunshine Beach                                                         August 2024