Abstract: | This paper analyses the processes which govern structural response, and uses observations of strong earthquake ground motion to propose quantitative extrapolation of pseudo relative velocity spectral amplitudes to long (100 > T > 1 s) periods. This will eliminate the current difficulties with rough estimation of long period spectral amplitudes and will open new possibilities by enabling the strong motion hazard calculations to be extended to the same long period band. So far, the scaling equations of response spectrum amplitudes have been valid only up to periods less than several seconds. The design of long structures and of structures on multiple distant supports requires knowledge and specification of design ground motions well beyond 1–10 s periods. With the results presented in this paper it will be possible to compute site-specific uniform hazard spectra and associated synthetic accelograms for essentially all long period response problems. |