The article is devoted to the study of the influence of the choice of the calculation scheme on the accuracy of the engineering assessment of the behavior of monolithic reinforced concrete frame structures. Various types of models are considered: rod, plate and volumetric, taking into account both linear and physical nonlinearity. It is emphasized that the adequacy of accounting for the spatial interaction of elements, the reliability of the assessment of forces and stresses, as well as the possibility of optimizing design solutions, especially under seismic and wind loads, depend on the correctness of the adopted calculation scheme. As part of the study, a single-span reinforced concrete frame was modeled, the load on which varied from 5 to 55 kN. A comparison of the calculated results with experimental data was carried out. It is shown that models that take into account physical nonlinearity and use more detailed modeling (for example, volumetric finite elements) provide the greatest accuracy in predicting deflections and stresses in the structure. The obtained results confirm the necessity of a careful approach to the choice of the calculation scheme in design, especially in the design of high-rise buildings and structures in seismically dangerous areas. Recommendations are made on the rational use of models of different levels of detail in engineering practice.

Keywords: linear calculation, nonlinear calculation, frames, reinforced concrete, deflections, modeling

This research presents the methods and conclusions obtained from modeling a composite wall panel with a wooden frame and polystyrene concrete core in the Lira-SAPR program, used in the construction of low-rise buildings for residential and commercial purposes. The findings were compared with the results of panel tests at the research laboratory of the Pacific State University (hereinafter TOGU).

Keywords: linear calculation, panel construction, low-rise construction, LIRA-SAPR, modeling

The article deals with the issues of assessing the effectiveness of the construction and operation of metal corrugated pipes. The characteristic features and difficulties of the operation of corrugated metal culverts in areas of permafrost distribution are revealed. The characteristics of the main defects of culverts are systematized. The features of thermophysical calculations of metal corrugated pipes on a frozen base are analyzed in detail. Recommendations are given on the application of the most effective technical solutions in the construction of corrugated metal culverts on permafrost soils.

Keywords: highway, culverts, metal corrugated pipes, thermal conductivity, permafrost soils