RFI - Attachment C - Slope Stability Assessment and Geotechnical report · MCU20/0026

Project No. 1-22543                                                                                                           Page | 13
June, 2020
Ref: 1-22543, 2020-05-20, BR SSA VER 1
Sanya Holdings – Slope Stability Assessment and Geotechnical Report - Proposed Residence, 40 Park Crescent, Sunshine Beach




TABLE 5            RISK CRITERIA
          Situation                     Suggested Tolerable Loss of Life                             Suggested Acceptable Loss of
                                       Risk limit for the person most at risk                      Life Risk limit for the person most
                                                                                                                  at risk
     Existing Slope                                      10-4 / annum                                          10-5 / annum
 Existing Development                                    10-4 / annum                                          10-5 / annum
New Constructed Slope                                    10-5 /annum                                           10-6 /annum
  New Development                                        10-5 /annum                                           10-6 /annum
  Existing Landslide                                     10-5 /annum                                           10-6 /annum
Notes:
 “Existing Slopes” in this context are slopes that are not part of a recognizable landslide and have demonstrated non-failure
  performance over at least several seasons or events of extended adverse weather, usually being a period of at least 10 to 20
  years.
 “Existing Development” includes existing structures, and slopes that have been modified by cut and fill, that are not located on or
  part of a recognizable landslide and have demonstrated non-failure performance over at least several seasons or events of
  extended adverse weather, usually being a period of at least 10 to 20 years.
 “New Constructed Slope” includes any change to existing slopes by cut or fill or changes to existing slopes by new stabilisation
  works (including replacement of existing retaining walls or replacement of existing stabilisation measures, such as rock bolts or
  catch fences).
 “New Development” includes any new structure or change to an existing slope or structure. Where changes to an existing
  structure or slope result in any cut or fill of less than 1.0m vertical height from the toe to the crest and this change does not
  increase the risk, then the Existing Slope / Existing Structure criterion may be adopted. Where changes to an existing structure
  do not increase the building footprint or do not result in an overall change in footing loads, then the Existing Development
  criterion may be adopted.
 “Existing Landslides” have been considered likely to require remedial works and hence would become a New Constructed Slope
  and require the lower risk. Even where remedial works are not required per se, it would be reasonable expectation of the public
  for a known landslide to be assessed to the lower risk category as a matter of “public safety”
 Acceptable risks are usually considered to be one order of magnitude lower than the Tolerable Risks.
 It is important to distinguish between “acceptable risks” and “tolerable risks”.
 Tolerable Risks are risks within a range that society can live with so as to secure certain benefits. It is a range of risk regarded as
  non-negligible and needing to be kept under review and reduced further if practicable.
 Acceptable Risks are risks which everyone affected is prepared to accept. Action to further reduce such risk is usually not
  required unless reasonably practicable measures are available at low cost in terms of money, time and effort.




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