The paper presents the results of full-scale experimental studies on the pattern of propagation of seismic blast waves in the soil and the behavior of the underground cylindrical thin-walled shell under seismic effects of underground instantaneous explosions. It was established that the rise time of the maximum of the underground structure in the waveform does not correspond in value with the time of the rise of the maximum of the soil environment surrounding the underground structure. From the above it follows that, with moderate attenuation, the logarithmic decrement is the ratio of the energy scattered in one cycle to the doubled maximum potential energy of the cycle. The results obtained are important in engineering analysis and prediction of the behavior of underground thin-walled structures.

The paper presents the results of full-scale experimental studies on the pattern of propagation of seismic blast waves in the soil and the behavior of the underground cylindrical thin-walled shell under seismic effects of underground instantaneous explosions. It was established that the rise time of the maximum of the underground structure in the waveform does not correspond in value with the time of the rise of the maximum of the soil environment surrounding the underground structure. From the above it follows that, with moderate attenuation, the logarithmic decrement is the ratio of the energy scattered in one cycle to the doubled maximum potential energy of the cycle. The results obtained are important in engineering analysis and prediction of the behavior of underground thin-walled structures.