Geotech Report · OPW26/0094

Project No. PG-10899                                                                                                    Page | 4
November 2023
Ref: PG-10899, 2023-10-16, GR VER 1
DD Sunnyside CD Sunnyside Pty Ltd – Geotechnical Investigation - Proposed Residence, 30 Mossman Court, Noosa Heads




4.0 GEOTECHNICAL MODEL

The subsurface profile encountered in borehole BH01 generally consisted of a
surficial concrete layer associated with the driveway, overlying very loose to loose
sand fill to a depth of 2.3m, overlying natural sands that were generally medium
dense to dense, becoming indurated at a depth of 6.6m, and continued to the
termination of borehole BH01 of 9.0m.

In HA02, loose silty sand fill was encountered to a depth of 0.6m, overlying loose
sand fill to the termination depth of 1.0m.

Table 1 presents a summary of the encountered subsurface profile. Detailed
borehole record sheets are appended to this report.

TABLE 1                            SUBSURFACE PROFILE SUMMARY

                                                          NATURAL
                                                           SAND
BH No.                FILL                                                                                           BH TD
                                                                Dense to Very Dense
                                       Medium Dense to Dense
                                                                    (Indurated)
  BH01              0.0-2.3                   2.3-6.6                  6.6-TD                                         9.0
  BH02              0.0-TD                      NE                       NE                                           1.0

Notes:
1. All depths in metres below ground level at time of investigation.
2. NE - Not Encountered; TD - Termination Depth.

5.0 GROUNDWATER

Groundwater was noted in borehole BH01 at a depth of 2.8m at the time of drilling.
Water levels can be expected to similar to the tidal levels of the neighbouring canal
and may vary with seasonal and climatic conditions.

Typically the groundwater levels in the area are encountered at levels of
approximately RL 0.5m to RL 1.0m. Fluctuations of +/- 0.5m are typically noted in the
area.

Increases in the groundwater levels often occur following significant rainfall events
(floods) with the groundwater levels to as much as RL 1.5m to RL 2.0m being noted in
the area.

6.0 POTENTIAL GROUND SURFACE MOVEMENTS

On the basis of the field testing results, and the depth of fill encountered, the site
must be classified Class P, in accordance with AS 2870-2011, by definition. This does
not necessarily mean the site is a problem, just that it is excluded from other
classifications.

From a reactivity perspective, the investigation and laboratory test results indicate
that the development site would be classified Class ‘S’, slightly reactive, in