OPW052025 Report - Part 2

Tables
Table 1: Summary of CBR Laboratory Results .................................................................................................................... 10
Table 2: Stability Risk Levels ...................................................................................................................................................... 14
Table 3: Details of Qualitative Risk Assessment for Property (AGS 2007) ............................................................... 15
Table 4: Retaining Wall Design Parameters.......................................................................................................................... 23

Text Figures
Text Figure 1: Sketch of proposed works (provided by SQ)............................................................................................. 2
Text Figure 2: May 2024 aerial image of lot and surrounds (courtesy Queensland Globe)................................. 3
Text Figure 3: Topography of site and surrounds, hillshade applied (courtesy Qld Globe) ................................ 4
Text Figure 4: Veiw from lowest intermediate knob (LHS) & along driveway alingment above
      existing sheds (RHS) ............................................................................................................................................................ 5
Text Figure 5: Looking south-west from saddle (LHS) & north-east at sidelong cut (RHS) ................................ 6
Text Figure 6: View of final rise to house site, looking west ............................................................................................ 6
Text Figure 7: Looking north over proposed house site ................................................................................................... 7
Text Figure 8: Extract of Gympie Surface Geology Map .................................................................................................... 8
Text Figure 9: View of weathered phyllite in cutting adjacent to sidelong section of track ................................ 8
Text Figure 10: Finished excavation - test pit TP3 ............................................................................................................... 9
Text Figure 11: Extract of NC Landslide Hazard Overlay Mapping.............................................................................. 13
Text Figure 12: Extract from Slope/W Analysis (Section A-A'- including adverse groundwater
      condition) .............................................................................................................................................................................. 16
Text Figure 13: Extract from Slope/W Analysis (Section B-B'- including adverse groundwater
      condition) .............................................................................................................................................................................. 17
Text Figure 14: Concept drainage arrangements ............................................................................................................... 18
Text Figure 15: Footing depth required to minimise the risk of undermining and surcharge loading ......... 22

Appendices
Appendix A                      Test Pit Logs & Explanatory Notes
Appendix B                      Laboratory Test Certificates
Appendix C                      AGS 2007 Practice Note Guidelines for Landslide Risk Management & Qualitative
                                Terminology for Use in Assessing Risk to Property
Appendix D                      Limitations

Figures
Figure 1: Site Plan




Geotechnical Investigation & Slope Stability Assessment
9 April 2025 | 25050-001-Rev0                                                                                                                                                                 iv