This study proposed a relaxed similarity rule under gravity field in which the performance verification for disaster structures can be conducted. In the proposed similarity rule, relaxation of a conventional similarity rule was attempted in a way that the basic unit of length was divided into geometrical length and displacement. The proposed similarity rule was verified for static and vibration response through a scaled experiment for a cantilever beam. Numerical simulation for impact loading on a cantilever beam validated the applicability of the proposed similarity rule to impact problems.
