Simulation of structural response under high-frequency ground excitation

The structural response to high-frequency ground motions is complicated due to the involvement of local-mode vibration. At present such a characterist ic is not well recognized and this can cause confusion over the analytical and experimental modelling of the corresponding response and damage. The fa ct that most existing regulatory guides for limits on allowable constructio n vibrations are necessarily simplified for administrative reasons calls up on the derivation of more sophisticated approaches for special cases. This requires accumulation of pertinent experimental evidence. This paper attemp ts to provide some insights into the local-mode dynamic response characteri stics, with emphasis on appropriate modelling techniques and experimental m easurements. A preliminary testing program is reported, in which efforts we re made to reproduce high-frequency response with a reduced scale reinforce d concrete model with shaking table facilities. The results demonstrate the dependence of the response amplitudes with the excitation frequency. On a ppv-basis, the current test results indicate that a substantial increase of the allowable ppv value from those specified by various standards may be c onsidered for structural damage to reinforced concrete building structures. More analytical and experimental data are needed for further evaluation of the local-mode effects and to quantify their impact on the structural dama ge process. Copyright (C) 2001 John Wiley & Sons, Ltd.