Appendix E - Geotechnical Report

                              PROPOSED RECONFIGURATION OF A LOT
                              216 BLACK MOUNTAIN ROAD, BLACK MOUNTAIN

5.0       INVESTIGATION FINDINGS
5.1        Geology
The 1:100,000 scale Gympie Special Geological Map (Sheet 9445 and Part 9545, DME 1999) indicates that
the site is underlain by strata of the early to middle Triassic age Kin Kin Beds (grey shading) comprising
“arenite, argillite, phyllite”. An extract from the geological map is shown in Text Figure 6 below.




                                                                           Approximate site location




Text Figure 6: Extract from Gympie geology map

5.2       Subsurface Conditions
Detailed descriptions of the subsurface conditions encountered in the test pits are provided in the test pit
reports attached in Appendix A, along with definition sheets which describe terms and abbreviations used
on the reports.

Test pits generally encountered similar subsurface profiles which can be summarised as follows:
         Topsoil comprising stiff silty clay to depths of 0.1 m to 0.2 m BGL; underlain by
         Residual material comprising mostly very stiff, medium to high plasticity silty clay, occasionally
          with gravel to depths of between 1 m and 1.7 m BGL; underlain by
         Extremely weathered material comprising stiff to very stiff, high plasticity, silty clay with gravel
          and cobbles to depths of between 2 m and 2.7 m BGL; underlain by
         Highly weathered to moderately weathered, very low strength, pale grey phyllite, with a thinly
          laminated fabric; typically excavatable to a depth of about 0.4 m to 0.7 m, before bucket refusal
          was encountered.

No fissured clays were encountered in the test pits. Low strength phyllite rock was also observed in the
cutting on the southern side of Black Mountain Road, opposite the allotment entrance.

Fill was not encountered in the test pits, but may be expected on the sidelong batter formed along the
proposed alignment of the new driveway for Lot 1.
Groundwater seepage was not encountered in any of the test pits at the time of investigation, with soils
being dry to moist. However, it should be noted that groundwater seepage may develop at shallow depths
within permeable horizons or at soil/rock interfaces, particularly following periods of heavy or prolonged
rainfall.




19 June 2018
Report No. 17427-001-Rev0                                5