ECM_22343520_v1_Geotechnical Investigation

                                         PROPOSED RENOVATIONS
                                         2 ARAKOON CRESCENT, SUNSHINE BEACH

            1.0        INTRODUCTION
            This report details the results of a geotechnical assessment undertaken for the proposed renovations to an
            existing residence at 2 Arakoon Crescent, Sunshine Beach. The investigation was carried out by Tectonic
            for Christopher Kelly, generally in accordance with Proposal P22631-Rev0 dated 4 October 2022. Adapt
            Planning are the consulting town planners for the project.
            Royal Haskoning Australia DHV (RHDHV) has provided a coastal engineering report, detailing a review of
            the Erosion Prone Area associated with the coastal building line at the subject site (Ref. PA3303, Status
            S0/P01.01, Rev R1, dated 20 February 2023).
            A site investigation ‘soil test’ report was completed by Australian Soil Investigations (ASI, Ref. Report No.
            220343(S), dated 22 September 2022). Tectonic conducted three additional standalone dynamic cone
            penetrometer (DCP) tests down the main high dune face and near the dune toe for an assessment of the
            density of the underlying sands.
            This report presents the results of the geotechnical investigation and slope stability modelling to address
            possible slope failure following a hypothetical future sea surge/storm event nominated by RHDHV, along with
            associated geotechnical recommendations and comments.

            2.0        PROPOSED DEVELOPMENT
            Preliminary architectural drawings by Aboda Design Group were supplied to Tectonic
            (Ref. Drawing Nos. WD.101 to WD.601 [not inclusive], Issue DA, dated 21 September 2022). Based on the
            provided drawings it is understood that the proposed development will comprise partial demolition of the
            existing residence and pool, although some of the structural elements will be retained for future utilisation
            (subject to the findings of the geotechnical investigation and assessment by structural engineers).

            The proposed renovations would be superimposed over the existing footprint, extending to two storeys
            height. The northern edge of the building would be excavated into the ground for a garage level and cellar
            room, which will have a pool positioned directly above partially cantilevered towards the dune slope to the
            east. Provided sections indicate that excavations up to about 2 m deep will be required, which will be
            retained.

            Although the footprint does not extend significantly beyond the existing building envelope, following
            demolition, it is anticipated that some form of temporary retention may be required, especially where
            excavations extend close to site boundaries or existing structures/elements (to remain). Filling is anticipated
            to be less than 1 m high.
            The proposed layout and some cross-sectional views are provided in Text Figure 1 overleaf.




             24 February 2023
             Report No. 22484-001-Rev0                              1
Document Set ID: 22343520
Version: 1, Version Date: 16/03/2023