Simulation of strong earthquake motion by explosions — experiments at the Lyaur testing range in Tajikistan

Strong motion data of 10 controlled explosion experiments conducted in 1977 at the Lyaur testing range in the Republic of Tajikistan are revisited. The explosions were detonated in arrays, with time delay between detonation of array lines. Ground accelerations, as large as 1.6g, were recorded at 4 sites by SMA-1 accelerographs. The records were recently digitized and processed with modern accelerogram data processing software. The amplitude and spectral characteristics of these data are here compared with those of strong earthquake shaking data and other published explosion data. The comparison of the Fourier amplitude spectra with estimates by recent empirical scaling laws for strong ground motion, in the near-field of earthquakes, suggests that such explosions can offer powerful possibilities (at present forgotten and neglected) for testing of almost full-scale structures (1/2 to 1/3 scaled models). It is suggested that by going into rather than avoiding the nonlinear zone surrounding the explosions, new testing methods can be developed to simulate near-field nonlinear strong motion of soft soils, found in most metropolitan areas in the seismically active regions.