Geotechnical Report (1) · MCU21/0212

                               PROPOSED RESIDENCE
                               66 SEAVIEW TERRACE, SUNSHINE BEACH

1.0      INTRODUCTION
This report details the results of a geotechnical investigation undertaken for a proposed residential
development at 66 Seaview Terrace, Sunshine Beach (‘the subject site’). The investigation was carried out
by Tectonic for Catherine and Gavin Deane, in accordance with Proposal P21519-Rev0 dated 8 September
2021. Pivotal Perspective are the consulting town planners and project managers for the development.
Haskoning Australia (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. PA2906-RHD-ZZ-XX-RP-Z-
0001, Status P01.01.S0, dated 28 October 2021).
The geotechnical investigation comprised drilling of boreholes at three locations; one using a tracked vehicle
mounted rotary rig; the other two by hand auger methods at the toe and crest of the dune. Dynamic cone
penetrometer (DCP) testing was also conducted along with geotechnical laboratory testing of selected soil
samples.
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 were supplied to us (Ref. Shaun Lockyer Architects, Project No. 0375,
Dwg. No. 000.00 to 400.02, Rev C, dated 20 October 2021).

The drawings indicate that it is proposed to construct a building of three storeys. The lowest storey would be
completely in-ground to the western side of the structure, and the uppermost level would be only partially
enclosed. The centre storey would have a cantilevered frontage extending around 3 m from the eastern edge
of the building, mimicked above by the third storey. A mixture of masonry, stonework, brickwork and concrete
walls; with complimentary wooden cladding and shutters also spread across the exterior.

A swimming pool would occupy the strip between the northern side of the residence, being mostly above
ground to the east; with a small section expected to be in-ground to the west. A concrete shell is indicated for
the pool, with a glass eastward facing front towards the beach.
To accommodate the lower level being ‘dug in’ to the dune, on the upslope side, bulk excavations against
the western boundary with Seaview Terrace are expected to reach around 3.5 m below ground level (BGL).
Excavations will therefore extend close to some of the site boundaries and, therefore, temporary retention
will be required. Isolated deeper excavations may be required for underground services and footings or
other specific elements.
Text Figure 1 below presents a cross sectional view of the proposed development.




Text Figure 1: Section through proposed residence, looking north (courtesy Shaun Lockyer Architects)




23 November 2021
Report No. 21370-001-Rev0                                 1