Introduction. This paper presents the processing and investigation of real seismic data in order to study the impact spectra and response of the oscillator at various damping levels.

The aim. Determination of the maximum, practically significant damping percentages using an informative, simple technique based on the amplitudes of the reaction spectra.

Materials and methods. Accelerograms were processed using Microsoft Excel and SeismoSignal software from SeismoSoft.

Results. A spectrum (impact spectrum) was constructed for each direction, and the total spectrum was calculated using the «Square Root of the Sum of Squares (SRSS)» method. The response spectrum of a system with one degree of freedom (oscillator) was compared with the impact spectrum. The total response spectra were calculated using three methods, and based on the analysis, the most acceptable one was identified. To analyze the damping properties, a family of spectral curves with different damping percentages was constructed for each axis. The maximum damping percentages, which are of practical importance, were determined using a developed technique based on the analysis of the maximum amplitudes of the response spectra.

Conclusions. It follows from the obtained results: the maximum values of the spectral power densities of impacts and reactions are different for periods in all three directions; the maximum damping percentages are different for each of the directions.

 

The problem of the interaction of a structure with an elastic half-space is of practical interest for a number of reasons. Firstly, the structure and the soil on which it rests form a connected dynamic system, and the feedback from the structure to the soil layers can be significant. In this case, for example, the seismic action cannot be determined independently of the characteristics of the structure. Second, it is not always possible to select or model ground motion records that are representative of the specific ground conditions of a construction site. In this case, it is desirable to take into account the characteristics of the foundation array in the calculations. Thirdly, the soil can also interact with the structure, causing changes in its stress state.

The problem of dynamic interaction of structures with the foundation and the transmission of vibrations through the ground is associated with such sciences as engineering seismology, theory of seismic resistance, mechanics of a deformable solid body. This article deals with the problem of setting the design seismic impact on the structure.

The paper presents the results of a study of the strength, non-viability, reliability of structural elements of two reinforced concrete tanks for storing clean water with a capacity of 750 m3 each, which are located in the Khovaron mahalla of the city of Dushanbe, and recommendations are given on the possibility of using the structures for their intended purpose. It should be noted that the city of Dushanbe is located in a 9-point seismicity zone according to the maps of the general seismic zoning of the Republic of Tajikistan.

The area of Tajikistan is 143.1 thousand km², while about 93% of its territory is occupied by mountains, the maximum heights of which reach more than 7000 m above sea level. The rest of the country (7%) is plains and valleys with heights from 300 to 1000 m above sea level. Such a significant range of heights is explained by the location of the study area in the junction zone of the Tien Shan fold system and the Alpine-Himalayan belt and leads to a wide variety of geological, hydrogeological, landscape-climatic and seismic conditions, analysis of the consequences of destructive earthquakes is of great importance for solving scientific and practical problems in the field of seismology, as well as problems of earthquake-resistant construction. The analysis of consequences of destructive earthquakes is important for solving scientific and practical tasks in the field of seismology and problems of earthquake engineering. One of the main sources of seismic resistance assessment of buildings and structures, along with theoretical and experimental studies, is engineering analysis of the consequences of strong earthquakes. This article deals with the effects of earthquakes on the earth's surface. The example of the following devastating earthquakes that occurred in Tajikistan, the impact of these seismic events on various types of residential buildings built from local materials is considered, and the main reasons for the observed nature of deformations and destruction are discussed.

The paper presents the main results of the visual inspection of technical condition of the cultural and historic building structures in Tajikistan and establishes cause-effect relations of their temporary physical deterioration, assessment of building structures and recommendations for development of an integrated system approach to preservation of historic stone buildings.