ECM_22343520_v1_Geotechnical Investigation · 132000.200173.1

                                         PROPOSED RENOVATIONS
                                         2 ARAKOON CRESCENT, SUNSHINE BEACH

            3.0        METHOD OF INVESTIGATION

            3.1         Fieldwork
            An experienced geotechnical engineer from Tectonic undertook a site walk-over on 5 December 2022 to
            visually assess 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.

            At the time of the walkover three standalone DCP tests (denoted DCP1 to DCP3) were conducted down the
            high dune face. DCP1 was conducted near the eastern property boundary, DCP2 at an intermediate point,
            around half-way down the dune face, and DCP3 near the dune toe. All DCPs were completed to practical
            refusal. DCP reports are attached in Appendix A, with locations shown in Figure 1.

            4.0        RESULTS OF INVESTIGATION
            4.1        Site Description
            The site is formally described as Lot 783 on RP48111, covering an area of about 866 m2, with frontage to
            The Esplanade along the western boundary. At the time of the investigation the site featured an existing
            residence of mostly two storeys, with a single level garage and mostly inground pool along the western
            boundary. A levelled terrace area was located along the eastern edge of the residence which was supported
            by a timber sleeper wall about 0.5 m to 1 m high. Based on an external assessment, visible areas of the
            existing structures appeared to be in relatively good structural condition, with no obvious signs of distress
            (e.g. cracking, misalignment etc.) which would be indicative of global slope instability. Cracking <10 mm
            wide was observed in parts of the rendered finish, with corrosion noted within some of the fixings.

            Two to three storey houses and low-rise unit buildings were generally present in the vicinity of the site, of
            varying age and construction methodology. The areas around the residence featured garden beds, small
            bushes and scattered trees. A large pine tree adjacent to the south-eastern corner of the residence was
            noted to be tilting and exhibited a ‘J’ shaped curve, and appeared to be undermined by an erosion scour
            which extended down the high dune face below.

            Patchy vegetation was observed along the upper part of the high dune face, with relatively dense vegetation
            present further downslope comprising ground cover plants and a small number of trees, such as Banksia
            and She-Oak.
            The asphalt seal and kerb and channel along The Esplanade in the vicinity of the site was noted to be in
            good condition with no obvious signs of cracking or misalignment. An aerial image of the site and surrounds
            is provided on Text Figure 2 overleaf.




             24 February 2023
             Report No. 22484-001-Rev0                              3
Document Set ID: 22343520
Version: 1, Version Date: 16/03/2023