Energy-Based Evaluation of Dynamic Soil-Structure Interaction Process Under Seismic Impact from Explosion

This study presents the results of instrumental observations of the interaction process of an underground structure with the soil environment under explosion-induced seismic impact. During seismic impact, the soil imparts kinetic energy to underground structures, the value of which depends on the contact area of the structure and the soil and the conditions of interaction. In this regard, the energy-based evaluation of the process of joint vibration of the underground structure and the environment under explosive seismic waves is of great significance. The analysis of energy release in terms of frequencies shows that the energy of seismic radiation at different frequencies of the spectrum is not the same, and there is a well-defined maximum in the energy spectrum at small equivalent distances, i.e. at a certain frequency value much more energy is released than at other frequencies. Mathematical expressions are provided for calculating the total energy of ground vibrations, estimated proportion of energy propagating in the soil, and the energy received by the underground structure during their interaction. A formula is proposed for calculating a dimensionless coefficient of the vibration process, indicating the share of energy transmitted through the soil to the underground structures. Three zones are identified that characterize the relationships of the forces of interaction in the contact area. The first is the zone with a linear relationship between the force and the deflection of the structure. Then, in the next zone, the proportionality between the values is violated with the loss of the elastic nature of the interaction. In the third zone, the underground structure slides relative to the ground. Aspects of the interaction of a thin-walled structure with the soil are considered. Calculations show that the obtained relationships can be used with sufficient accuracy to evaluate the seismic intensity of explosive seismic waves.