Additional Geotech Investigation 22.02.01 From Douglas Partners - 95120.01.R.001 · OPW21/0315

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2.     Field Work Methods

The field work for this investigation was undertaken on 22 December 2021, and comprised the drilling
and sampling of three additional bores (designated as Bores 2 to 4). The approximate bore locations
are indicated on Drawing 1 attached.

The bores were drilled to 6.0 m depth with a 4WD ute mounted Jacro 200 drilling rig using continuous
flight augers fitted with a tungsten carbide (TC) bit. Dynamic cone penetrometer (DCP) testing was
carried out to assess the relative density of the subsurface soils. On completion, a PVC standpipe was
installed in Bore 3 with the remaining bores backfilled with spoil which was tamped into the holes.

The field work was undertaken by experienced geotechnical personnel who logged the bores and
collected samples for visual and tactile assessment, and for subsequent laboratory testing. Strata
identification was undertaken through observation of cutting returns and recovered samples.


3.     Field Work Results

The subsurface conditions encountered in the bores are described in detail on the attached borehole
logs, together with accompanying notes which define the classification methods and descriptive terms
used. The depths were measured below existing surface levels at the time of investigation.

In summary, the subsurface conditions encountered in the bores typically comprised fill overlying
natural sands. The subsurface conditions encountered are further described below:
•    Fill: Silty sand fill was encountered in the bores to between 2.2 m and 2.3 m depth. The relative
     density of the silty sand fill initially was typically ‘loose to medium dense’ becoming ‘medium
     dense’ and ‘dense’ with depth. In the absence of documentation to confirm the fill was placed in
     a controlled manner or to confirm the degree of compaction to an engineering standard was
     achieved, the fill is assumed to be ‘uncontrolled’.
•    Sands: Underlying the fill, natural sands were encountered in the bores. Initially, the relative
     density of the natural sands was typically medium dense and dense, grading very dense
     (indurated) below 4.8 m and 5.4 m depth, and continued to the termination of the bores at 6.0 m
     depth.

Groundwater seepage was encountered at between 1.65 m and 1.85 m depth at the time of
investigation. It should be noted however, that groundwater depths and ground moisture conditions
are affected by climatic conditions, surface and subsurface drainage conditions, and human influence
and will therefore vary with time. Groundwater levels are expected to be similar to the water level in
the canal at the rear of the site, albeit somewhat a dampened response to tidal variations.




Proposed Residence                                                                  95120.01.R.001.docx
33 Wyuna Drive, Noosaville                                                                February 2022