Geotech Report - techtonic · RAL22/0021

                             PROPOSED RESIDENTIAL DEVELOPMENT
                             39 PICTURE POINT CRESCENT, NOOSA HEADS

3.0      METHOD OF INVESTIGATION
As part of our assessment, a desk-top study was carried out comprising a review of published geological
maps, slope stability studies as well as Noosa Council (NC) planning overlays and site information.

An experienced engineering geologist from Tectonic undertook a site walk-over on 16 January 2023 to
visually assess any 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.

This was incorporated with a subsurface investigation comprising the drilling of two boreholes (designated
BHT-1 and BHT-2) in accessible areas across the site. Due to access constraints, boreholes were drilled
using hand augering equipment. The boreholes were taken to a target depth of 3 m below ground level
(BGL).

In-situ DCP testing was carried out from the ground surface and within each borehole. Boreholes were
backfilled on completion using spoil arising during drilling, with excess material slightly mounded at surface.
Additionally, a single in situ DCP test (denoted DCPT-3) was completed in a steeper part of the site
downslope to a depth of 3.6 m BGL.

Laboratory testing was not warranted due to the sandy nature of the subsurface conditions encountered.
A ‘soil test’ undertaken by Global Testing (Ref. Job No. 22-0439, dated 12 April 2022) was also reviewed as
part of this investigation, which included two hand auger boreholes taken to 1.5 m BGL towards the southern
corner of the existing residence.

Tectonic borehole locations are shown in Figure 1 attached at the end of this report, with borehole and DCP
logs presented in Appendix A, together with explanatory notes. Borehole coordinates were recorded using
a hand-held global positioning system (GPS).

The results of the desk-top study and walk-over survey are included in Section 4 below.


4.0      RESULTS OF INVESTIGATION
4.1      Site Description
The site is formally described as Lot 2 on RP220514, covering an area of about 1447 m2, with frontage to
Picture Point Crescent along the southern boundary. At the time of the investigation the site featured an
existing residence, positioned over central and southern portions.

Similar sized residential blocks were present to the east and west of the site, which also contained
residences of between one and three storeys (generally increasing in height downslope/away from Picture
Point Crescent).

A recent aerial image of the site and surrounds is shown in Text Figure 2 overleaf.




10 February 2023
Report No. 22511-001-Rev0                              2