Characteristics of Impact-induced Ground Vibration and Predictive Method

摘要

Ground vibrations occurred in explosive demolition of structures are induced by explosive blasting and ground impact of disintegrated mass concrete as welL The waveform record from explosive demolition is divided distinctly into early part of blast-induced vibration and later part of impact-induced one. The two wave patterns show very different characteristics in frequency contents and duration of ground vibration, which may have a different effect on adjacent structure. In this paper, ground vibration records were analyzed, which were measured from 13 cases of building demolition projects in Korea Dominant frequencies from building demolition blasting were compared with those from construction blasting. When the principal frequency is defined as that associated with the greatest amplitude pulse, the dominant frequencies from building demolition blasting was shown to fall into the range between 0 and 20 Hz. These low frequency ground motions may produce higher building strains than are produced by the highfrequency motions from construction blasting. Portable impact testing apparatus was designed and constructed so as to predict the ground vibration from building demolition in design stage. Field application of the apparatus was carried out It was shown that one could get useful information, in advance, on the possible environmental impact due to demolition work.