Abstract:

The arch dam design specification (SL282-2003) provides an allowable safety factor of 3.5 for
abutment stability analysis, which is higher than Besides allowable value of 3.0 specified for gravity dams.
Accordingly, the engineering structural reliability standards should also provide a different allowable
reliability index, which is currently not available in GB50153-2008. Both arch and gravity dam
specifications suggest partial factors for the limit state design method, but investigations on their engineering
applicability appear in sufficient. This paper is a continuation of the previous relevant studies on gravity
dams and focuses on establishing allowable reliability index for arch dam abutment stability analysis. This
criterion is subsequently used in assessing the applicability of the suggested partial factors. The research
results confirm that an allowable reliability index of 4.45 should be specified in order to make the stability
analysis at the same level of risk control to the allowable safety factor of 3.5. Using the approach of ‘Ratio
of Safety Margin’ proposed by the authors, it isconcluded that the partial factors suggested in specification
DL/T5346-2006 is reasonable for practical engineering purposes.