Attachment C - Soil Survey Report · MCU18/0013

Project No. 1-20119                                                                                                                   Page | 14
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




The consequence is based on the proposed development and the effects on the property of the
specific hazards in Section 5.5.

The risk is then assessed based on the Risk Matrix from LRMPNG, 2007. The assessment is
summarised in Table 3.

TABLE 3             SUMMARY OF RISK TO PROPERTY
                                            Hazard                   Assessed                    Assessed                  Assessed Risk
Hazard           Area of Site
                                            Rating                   Likelihood                 Consequence                 to Property
                     Area Ia               Very Low                Barely Credible                   Medium                   Very Low
     A
                     Area Ib          Low to Moderate                   Unlikely                       Minor                    Low
      2.
    B                Area II          Low to Moderate                   Unlikely                     Medium                     Low
                 Overall Site –          Moderate to
                                                                  Unlikely to Likely               Insignificant           Very Low to Low
                   initially                High
    C
                 Overall Site –                                  Barely Credible to
                            3.        Very Low to Low                                                Medium                Very Low to Low
                  long term                                            Rare
Note:- 1. Refer Appendix B of “Practice Note Guidelines for Landslides Risk Management (2007)”.
           2. Assumes all cuts supported by engineer designed retaining walls.
           3. Assumes it’s addressed by landscaping and control of drainage and overland flow.


A review of the table above indicates that provided the recommendations outlined in this
report are carried out, the risk of slope instability occurring on the site has been
assessed as no higher than Low.

    5.7 Risk Determination and Evaluation - Persons
Evaluation of the risk to life must be carried out on a quantitative basis to be consistent and for
comparison with acceptance criteria. To do this, the indicative probabilities given in Appendix C
of PNGLRM (2007) may be adopted as there are no other frequency/probability data. The
assessment results are shown in Table 4.

The analysis is based on formula 1 in Section 7 of PNGLRM (2007), i.e.:-

                                   R(LoL) = P(H) × P(S:H) × P(T:S) × V(D:T)
Where                  R(LoL) = The risk for Loss of Life
                       P(H) = Annual probability of the Landslide - based on Section 5.4
                       The other factors are outlined in Section 5.5.4

The acceptance criteria (Table 5) adopted for this assessment is outlined in Section 8 of
PNGLRM (2007) which suggests the following Risk to Life as outlined in Table 4.

Based on the assessment below, the risk to life for the three hazards has been assessed
to be Acceptable.