Currently, more and more unique industrial buildings and structures are being built in difficult geotechnical conditions all over the world. One of the most common factors complicating the design of facilities with a high level of responsibility from the point of view of geotechnics is construction in earthquake-prone regions. Seismic impacts lead to a loss of soil stability under dynamic influence and require the determination of nonlinear dynamic properties of soils for the subsequent design of structures on such grounds. To carry out a qualitative and quantitative assessment of the stability of the base of a nuclear power facility under dynamic loads, a series of special laboratory studies was carried out, including dynamic triaxial compression tests and low-amplitude torsional vibration tests in a resonant column. The base was represented by bulk sandy soils, soil samples were tested at full water saturation and in accordance with the regulatory and technical documentation of the Russian Federation. According to the results of dynamic triaxial compression tests, dilution potentials were determined for each of the soil samples taken from a depth of 0.8 to 9.0 m. As a result of low-amplitude dynamic tests performed using a resonant column, the corresponding resonant frequencies, shear modulus, and damping coefficients were obtained for each of the soil samples taken from a depth of 3.8 to 8.0 m. During the research, a computer program was implemented and tested to speed up the processing of test results, as well as improve the accuracy and reliability of the data obtained because of processing. The use of automated tools for processing laboratory test results significantly reduces the time required to complete research and improves the accuracy of processing. The tests performed made it possible to assess the dynamic stability of the projected structure at different intensities of the predicted seismic impact. Based on the data obtained, a computational model was created in the Plaxis geotechnical software complex, in which the behavior of a sand embankment under dynamic loads was modeled. An analysis of the stress-strain state of the base of the projected structure under seismic influence has been performed, considering the soil parameters determined based on special laboratory studies of the dynamic properties of soils. The assessment of the risk of loss of stability of the foundation soils at various levels of seismic impact is carried out based on the initial data on the predicted seismic impact.
Sobolev et al. (Thu,) studied this question.