Page 90 - Design Considerations Based on Quantitative Risk Assessments for Slopes
P. 90
Conclusion & Recommendation
Risk Criteria & Landslide Frequency
▪ Quantitative Risk Analysis case studies, which risk threshold results
are similar to those from social surveys, suggest that the public is
very tolerant to landslide risks. As such, the individual risk criteria
for Malaysia, with a tolerable range between 1/10 to 1/1000 per
annum is proposed in the interim. It is also proposed that this risk
criteria be shifted downwards, i.e., to the same standard as GEO HK
in 20 to 30 years, when sufficient budget could be allocated for
landslide mitigation strategies.
▪ The frequency of landslide for a specific slope could be determined
by plotting the rainfall threshold based on soil mechanics and IDF
curves on the same log-log chart. For a slope without records of
failure this method is the most objective and is proposed for QRA
purposes. This type of analysis however require extensive soil tests.
As such, hazard maps, which correlates well with FOS could be used
to choose those slopes that would require detailed analysis.
