Experimental investigation of structural response to generalized ground shock excitations

High-frequency ground motions (referred to as "ground shocks") of potentially damaging magnitude are produced from blasting and heavy construction activities. Up to now, quantification of the ground shock response and damage has remained empirical on the basis of general field observations. Systematic test data that allow for a rigorous interpretation of the response characteristics and calibration of analytical models are scarce. In this investigation, a unique experimental program was conducted to simulate the ground shock response on scaled reinforced concrete frame models with an electromagnetic shaker. Different response characteristics under high frequency excitations as compared to the familiar earthquake response are observed. In particular, the structural significance of local modes in high frequency response is clearly identified. The measured response allowed for the construction of spectral concrete strain curves for a given ground motion peak particle velocity (PPV), based on which a benchmark allowable PPV vs. input frequency relationship is obtained and is compared with relevant code provisions.