Attachment C - Soil Survey Report · MCU18/0013

Project No. 1-20119                                                                                                        Page | 7
March, 2018
Ref: 1-20119, 2018-03-02, BR VER 2
Sam Hopper – Slope Stability Assessment and Geotechnical Report - Proposed Residence, 24 Arakon Crescent, Sunshine Beach




TABLE 1             SUBSURFACE PROFILE SUMMARY
                                                Consistency based on DCP Tests and assuming
                                Fill - Very
                          (3)                                Full Sand Profile (m)               DCP Refusal HA Total
Location        RL (m)            Loose                                                                 (4)
                                                Very Loose to                      Dense to Very    (m)      Depth (m)
                                Sand (m)                         Medium Dense
                                                   Loose                              Dense
                                                                    0.70-1.80
                                                  0.00-0.70                          2.10-3.40
   HA01            27.0          0.00-TD                            2.00-2.10                        4.68      0.70
                                                  1.80-2.00                          4.50-4.68
                                                                    3.40-4.50
                                                                    0.00-1.10
   HA02            21.7          0.00-TD          1.10-3.70                          5.30-6.19       6.19      0.60
                                                                    3.70-5.30
 DCP03             24.7            NO             0.00-0.50         0.50-2.10        2.10-3.28       3.28        -
                                                                    0.00-1.20
                                                  1.20-2.20                          3.00-3.90
 DCP04             22.5            NO                               2.20-3.00                        5.78        -
                                                  3.90-5.40                          5.40-5.78
                                                                    3.90-5.40
  P05              20.7          0.00-TD             NT                NT               NT            NA       0.50
Notes:-
       1.     NE - Not Encountered; NA - Not Applicable; NO - Not Observed; TD - Total Depth; NT - Not Tested.
                                                       th
       2.     All depths below existing ground level (5 March, 2018).
       3.     RL's based on provided survey data.
       4.     Blows >20 per 100mm.

            3.6.2      Groundwater and Seepage

Groundwater seepage was not noted during the site investigation. However, seepage through
the upper granular material may be expected during and following periods of rainfall.

An onsite permeability test (P05) was undertaken on the site the results are included in
Appendix K and discussed in Section 8 of this report.

            3.6.3      Laboratory Testing

Due to the subsurface profile of sands intersected, no laboratory testing was carried out.
Samples were retained should any future testing be required.

    3.7 Evidence of Possible Instability
Existing Land Slips

No obvious visual evidence of landslide instability was noted on the site at the time of the site
walkover and investigation. However, vegetation obscures some areas of steeper slopes
towards the eastern side of the lot.

A review of air photos of the site does not indicate any likely areas of medium to large scale
instability on the natural slopes. Any existing small areas of instability would not be able to be
detected using this method due to photo scale.

Surface Scour

Minimal evidence of surface scour was noted on the site, however evidence was noted on the
pedestrian track exiting the south eastern corner of the lot. The majority of steeper areas were
generally well vegetated but overland flow paths could still produce continual scour paths during
major rain events.

Soil Creep

Slight leaning and/or bowed trunks of trees are generally considered to be indicative of soil
creep, with the affected trees being progressively tilted by the slow movement of soil down the
slope. The degree of tilting or bowing of these trees is considered to be a sign of relatively