For Fail Safe Structure, there is a requirement that the remaining structure at the time of a single load path failure must be capable of withstanding a minimum load P_yy.  This load P_yy is at least the load that causes the load path failure, plus an additional increment to account for the dynamic conditions of the breaking member.  While most data and analyses indicate that the dynamic magnification factor associated with the member failure is probably very small, the current guidance in JSSG-2006 requires that a 1.15 dynamic factor be applied to the redistributed incremental load unless another value is determined by test or analysis.  For non-metallic structure, the dynamic factor should be verified by testing.  Figure 1.3.9 illustrates the change in residual strength guidelines as a result of a load path failure.

Figure 1.3.9.  Schematic Residual Strength Guidelines for Fail Safe Structure