Slope Stability Report-21190-001-Rev0 Pomona Kin Kin Rd

Phil Brierley                                                                                    21190-001-Rev0
C/- NDD Constructions Pty Ltd                                                                       21 June 2021

DCP1 to DCP3 indicated the following subsurface conditions:
          Firm to stiff/loose to medium dense materials from the ground surface to depths between 1.7 m and
           2 m below ground level (BGL); then
          Stiff/medium dense (or stronger) materials to the DCP termination depths at 2.3 m to 2.9 m BGL.
DCP4 was undertaken centrally in the cut side of the level platform and indicated the following subsurface
conditions:
          Stiff/medium dense (or stronger) materials from the ground surface to 0.2 m BGL; then
          Hard/dense (or stronger) materials to the DCP termination depth at 0.4 m BGL.
All DCP tests encountered practical refusal at the termination depths, which is inferred to be on XW
materials or very low strength (or stronger) argillite/phyllite as observed in the upslope cutting.
DCP reports are attached at the end of this report.


2.2       Topography
As illustrated in Text Figure 5, the subject site is located on the south-westerly facing flank of a ridge which
traces the north-eastern property boundary. The proposed development areas are generally governed by a
south-westerly dipping well rounded spur, interrupted by previous earthworks.
During the site walk-over, topographic features specific to the site were noted, and ground slopes were
recorded using a hand-held clinometer. As stated previously, the proposed development areas had been
altered by previous cut and fill earthworks to create relatively level building platforms. Based on our site
observations it appeared that cut and fill earthworks in the order of about 3 m depth/height had been
undertaken to create the platform at the proposed shed site, with previous cut and fill earthworks at the
existing residence (proposed workshop location) estimated to range up to about 2 m deep and 1.5 m high,
respectively.

Existing cuttings typically were battered between about 30° and 40°, with some isolated areas being near
vertical along the existing driveway. Downslope fill batters typically ranged up to about 26°; however, a fill
embankment associated with the driveway was noted to be about 1.5 m high battered at about 35°. Ground
slopes across the proposed development areas were relatively level, with inferred surrounding natural
ground slopes ranging between about 18° and 25°.

                                          Existing Residence
             Approx. Proposed Shed Location

                                                                      Proposed Workshop




                                                                                Subject Site

                                                          Driveway Alignment




Text Figure 5: Image showing ground surface contours (courtesy NC Interactive Mapping)

Text Figures 6 to 8 overleaf illustrate the site conditions at the time of the walk-over inspection.




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