Attachment C - Soil Survey Report · MCU18/0013

Project No. 1-20119                                                                                                        Page | 13
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




           5.5.3       Consequence to Property

For the purposes of this study, a semi-qualitative measure of consequence to property will be
adopted, as outlined in Appendix C of PNGLRM 2007c.

If slope instability were to occur, the aspect of property most at risk would be the proposed
residential structure located on the subject part of the site.

Based on Appendix A of PNGLRM 2007c the residential structures at risk would be classified as
Importance Level 2.

Considering the above information the consequence to property for each of the hazards is as
follows:-

          Hazard A – Area I – Existing slopes – Minor to Medium
                      a - Medium, given adjacent roadway and underground services.
                      b - Minor, may affect some of the adjacent dune area or eastern edge of the
                       structure.
          Hazard B – Area II – Medium as could affect several areas of the site or adjacent sites
           during construction of the retaining walls.
          Hazard C – Initially Insignificant due to shallow soil profile but could be Medium if not
           addressed in the long term.

           5.5.4       Consequence to Persons

For the purposes of this study, the methodology as outlined in Section 7 of PNGLRM 2007, will
adopt the following assumptions with respect to persons on the lot. Different hazards have
been deemed to have varying probabilities based on their location on the site (Section 5.2):-

          The affected study site will contain a proposed residential dwelling.
          The probability of spatial impact (P(S:H)) - this has been based on the total width of the
           site exposed to possible instability compared to the total width of the proposed structure
           within that length. Assessed as 100%.
          Occupancy in any one dwelling - 4 persons.
          Proportion of time dwelling occupied - 50%.
          Probability of not being able to escape - 20%.
          Temporal Spatial Probability (P(T:S)) - Proportion of time dwelling occupied multiplied by
           the Probability of not being able to escape - 10%.
          Vulnerability (V(D:T)), (Appendix F - PNGLRM 2007):- 70%

Note: the consequences to Persons have not been assessed for hazard C prior to construction
as it is not considered applicable.

    5.6 Risk Determination and Evaluation - Property
Appendix C of “PNGLRM (2007)” outlines a method of assessing Risk to Property. The
calculation of likelihood is based on the estimate outlined in Sections 5.4.3 to 5.4.5 of this
report.