Appendix E_Geotechnical Investigation

                             PROPOSED UNIT DEVELOPMENT
                             PRECINCTS E2 & F, NOOSA SPRINGS

5.0      SUBSURFACE INVESTIGATION FINDINGS
5.1      Regional Geology
The 1:100,000 Series Gympie Special Geological Map (Sheet 9445 & Part 9545, First Edition 1999)
indicates that the site is underlain by Quaternary (Pleistocene) age ‘quartz sand’ (dune sand).

An extract of the relevant geological map is shown in Text Figure 8.




                                                                  Dune sand


                                                                  Indicative site location




Text Figure 8: Extract of Gympie geological map

5.2      Subsurface Conditions
The subsurface conditions encountered in the boreholes indicate that the site may be divided into two areas
(Refer Figure 1). Area 1 includes the boreholes drilled along the ridge line within Precinct F and across the
eastern part of Precinct E2. Area 2 includes the boreholes drilled within the flatter areas (south-eastern
section) of Precinct F and the western part of Precinct E2. Subsurface conditions from those two Areas are
summarised below:

Area 1: (Boreholes BH1, BH2, BH5, BH7 to BH13)

       Natural very loose to loose silty sand/sand to depths ranging between 0.4 m to 1.6 m BGL; over
       Medium dense to very dense silty sand/sand to depths ranging between 5.0 m and 6.0 m BGL;
        (termination of BH1, BH2, BH5, BH8 to BH13); and at BH7, underlain by
       Very dense indurated sand from 5.5 m to 6.0 m (termination depth).


Area 2: (Boreholes BH3, BH4 and BH6)
       Uncontrolled fill consisting of loose to medium dense silty sand to depths ranging from 0.55 m to 3.0
        m BGL; over
       Uncontrolled fill consisting of very stiff sandy clay to a depth of 3.6 m BGL (in borehole BH4 only);
        then
       Natural medium dense to very dense sand to termination depth of 6.0 m BGL.


Groundwater seepage was only encountered in boreholes BH6 and BH7 at depths of 4.6 m and 5.5 m BGL,
respectively. It should be notes that ‘perched’ groundwater seepage may develop at the interface between
the very dense sands soils and the less dese soils above, following periods of heavy or prolonged rainfall.


11 November 2015
Report No. 15193-002-Rev0                              7