Slope Analysis 18 Hay St

                                                                                                        ABN 51 640 311 842
                                                                                                        arcosgroup.com.au
                                                                                       Sunshine Coast | Brisbane | Gold Coast




1         INTRODUCTION
Arcos Unit Group Pty Ltd (Arcos Group) was commissioned to undertake a geotechnical investigation for the project
at the location described on the title page of this report.
This report outlines the results of the investigation, laboratory testing, analysis, and interpretive reporting on the
following items:
 Review of the existing slope stability hazards, their attributed risks and impacts of the proposed development in
  alignment with the practices set out within the Australian Geomechanics Society guidelines; and,
 Provide recommendations from a geotechnical context that will avoid or reduce any potential instability.
This report must be kept in entirety. The use of this document is exclusively undertaken in accordance with our terms
and conditions.

2         REGIONAL GEOLOGY
The site is in an area underlain by late Triassic to early Jurassic aged Myrtle Creek Sandstone, which typically
comprises “deeply weathered quartzose sandstone, siltstone, shale conglomerate, coal”. The encountered conditions
broadly agree with the weathering of the anticipated geological unit.

3         EXISTING STABILITY RISK
Local authorities prepare mapping tools to aid in assessing potential slope stability requirements. The mapping tools
are a “high level” approach where the site specific investigations are specific to a particular site/allotment. It is
important to note that where a site specific investigation and slope stability assessment are undertaken, they take
precedence.
Reference to the available overlays for the area show the allotment has been probably initially mapped as “Moderate”
in terms of landslide hazard.

4         GEOTECHNICAL INVESTIGATION
A geotechnical investigation has been undertaken for the property by Caloundra Soil Testing as detailed in their
report (Report No. 2487 Site Classification Report 21/03/2022). The investigation indicates a soil profile of loose/soft
soils underlain by very stiff clay below 0.7 m to 2 m depth.
This report is attached and the encountered conditions in this investigation have informed the analysis undertaken
by this office. Given this, where discrepancies exist between the encountered conditions in the referenced report and
the encountered conditions, our analysis cannot be considered to be accurate and reassessment will be required.

5         WALKOVER ASSESSMENT
Geotechnical comments are based on the factual findings of the investigation, best practice, local experience,
published correlations; however, are fundamentally founded in opinion and this should be considered.
Topographically, the site has a gentle slope to the south at angles of less than 5° to 10°. No obvious signs of disturbed
ground, tension cracks or hummocks were noted during the walkover assessment. A variety of vegetation ranging
from small shrubs to mature trees were observed. The mature trees were all observed to be typically vertical with no
misshapen or curved trunks. Misshapen or curved trunks are usually good indicators for previous slope instability.




Sunshine Coast | Brisbane | Gold Coast