Strength margin safety factor varies when different yield criteria are used
and some works about relationship between Druker-Prager yield criteria and strength margin safety factor have been studied with numerical method. However
theoretical relationship between them has not been deduced. Functional relationship between Druker-Prager yield criteria and strength margin safety factor
including point and global strength margin safety factor
has been put forward; and the result is that both point and global strength margin safety factor reach minimum when the inscribed cone yield criterion is used; while reach maximum when the expansive cone yield criterion is used. Meanwhile
the gravity dam’s stability of Xiangjiaba Hydropower Project has been investigated by strength margin FEM; and its result further supports the above conclusion.