Reference Document - Geotechnical Investigation Report - DBW24/0090 & RAP24/0025

                Rebecca Stead                                                                                              20248-001-Rev0
                                                                                                                         3 September 2020

                1.2       Method and Scope of Investigation
                As part of our assessment, a desk-top study was carried out comprising a review of published geological
                maps, ground level contour information, and Noosa Council (NC) landslide hazard overlays.

                An experienced geotechnical engineer from Tectonic undertook a site walk-over on 19 August 2020 to
                visually assess any indicators of past slope instability. The walk-over included assessment of soil
                exposures, surface drainage conditions, topography, evidence of erosion or past instability, and vegetation
                coverage/condition.

                The walkover was incorporated with a subsurface investigation comprising the drilling of boreholes at two
                locations (targeting the abovementioned main structural additions), using hang augering techniques to
                depths between 2.4 m and 3.0 m below ground level (BGL). Dynamic cone penetrometer (DCP) testing was
                carried out adjacent to each borehole location and downhole. The boreholes were backfilled on completion
                with spoil, with excess material slightly mounded at surface. Borehole co-ordinates were obtained using a
                hand-held GPS unit with a reported accuracy of +/- 3 m.

                Laboratory testing was not warranted due to the sandy nature of the subsurface conditions encountered.
                Reports of the boreholes and explanatory notes are attached. Test locations are shown in Text Figure 1
                above. The results of the desk-top study, walk-over survey and subsurface investigation are included in
                Section 2 below.

                1.3       Qualifications of Responsible Engineer
                This report has been prepared by Mr Scott Davis, an RPEQ with 12 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 information 1 indicates that the site is underlain by Pleistocene age dune sand (Ref: Text
                Figure 3), and is near the contact with the older Noosa Quartz Diorite formation.




                                                                     Noosa Quartz Diorite




                                                          Dune Sand

                                                  Approx. Site Location




                Text Figure 3: Extract of Gympie Special geology map



                1
                    Queensland Government, Department of Mines and Energy, 1:100,000 Gympie Special Geology Map, Sheet 9445 & Part 9545, 1999




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Document Set ID: 23080488
Version: 1, Version Date: 27/06/2024