Experimental Investigation of the Stability of Colonnades under Harmonic Excitation
The dynamic response of large historical block structures, as manifested by the response of the free-standing variable size drums colonnade of Baalbek due to strong ground shaking during earthquake events, is investigated experimentally for the purpose of predicting damage or collapse due to future earthquake events. Reduced single column multi drum models of scales 1/20 and 1/40 were subjected to harmonic excitations of varying amplitudes and periods on a 1D shaking table for up to 25 cycles noting collapse or survival. The results are compared to two dimensional simulations on UDEC as well as to the predictions of the Housner formula for single rigid block overturning by a half-cycle sinusoidal acceleration pulse. It is shown that the experimental results agree qualitatively with computer simulations for the reduced scale but cannot be directly extrapolated to full scale.