slope stability · MCU22/0172

Integra Partnerships                                                                           22339-001-Rev0
                                                                                            13 September 2022

testing, using the dynamic cone penetrometer (DCP) method, was carried out from the ground surface and
extending from the borehole termination depth to depths of 4.9 m to 5.5 m BGL.
The borehole logs and explanatory notes are attached to this report. The results of the desk-top study, walk-
over survey and borehole drilling are included in Section 2 below.

1.3        Qualifications of Responsible Engineer
This report has been reviewed by Mr Ashley Davey, an RPEQ with over 27 years of experience in
geotechnical engineering, including a number of slope stability projects on the Sunshine Coast.



2.0         DESCRIPTION OF EXISTING CONDITIONS
2.1        Geology and Subsurface Conditions
Available geological information1 indicates that the site is located at a contact between Anthropocene age
man-mad deposits (“Qhh”) comprising “gravel, sand and silt” and Pleistocene age parabolic dunes (“Qpd/2”)
comprising “quartz sand” (Ref. Text Figure 3).




                                                                Approx. site location




Text Figure 3: Extract from Laguna Bay Geology Map

The boreholes encountered relatively consistent subsurface conditions, summarised as follows:

           Natural Sands – initially comprising very loose to loose silty sand/sand to depths between 1.5 m
            and 2.2 m BGL, then becoming medium dense to the borehole termination depths (3 m BGL).

Results of the DCP testing completed below the borehole termination depths indicated inferred dense
sands at depths of 3.4 m BGL, then extending to the DCP termination depths of 4.9 m to 5.5 m BGL.

Groundwater was not encountered during drilling of the boreholes, with the soils being dry to moist.




1
    1:100,000 Laguna Bay Surface Geology, Sheet 9545, Compilation Map, DNRME, 2018




                                                              3/13