THE IMPACT OF CHANGING THE TYPE OF CROSS-SECTION OF COLUMNS OF FRAME BUILDINGS

Nowadays, the construction of multi-storey buildings is becoming increasingly important, leading to an increasing building density and the development of transport infrastructure. Recently, the volume of construction in areas exposed to vibrations of various nature has been steadily increasing. Constant impact of vibrations caused by external factors, such as traffic flows or industrial plants, on buildings can cause significant displacements of structural elements and increase noise levels, which is an additional negative effect on the safe operation of the building. Thus, the problem of controlling the impact of these vibrations on the reliability and durability of a building is becoming increasingly important. Reducing the impact of frequencies on the structural characteristics of structures and on the normal functioning of the human body is implemented by vibration isolation of buildings and structural monitoring systems. However, the effect of changing the cross-sections of structural elements has not been fully investigated. The aim of this work is to find rational cross-sectional shapes of columns in terms of material consumption and suitability for normal exploitation of multi-storey reinforced concrete frame buildings. To analyse the effect of changing the cross-section of the columns, 3 variants of the column cross-section were developed, in which the shapes and geometric dimensions were changed. The geometric characteristics of the cross-sections were calculated using the Arbat software, and the modal analysis was performed using the SCAD software package. As a result of the calculation, the interaction curves were obtained, which limit the area of the section's bearing capacity under the action of forces that can be applied to the section under analysis. In particular, the natural frequencies and shapes of vibrations were obtained, and the cross-sections of the columns were estimated by their area and moments of inertia. The changes in the type of column cross-section did not significantly affect the level of vibration frequencies of the building. However, it did change the material consumption and weight of the building by 24%, meaning that the values of the loads from the columns' own weight transmitted to the foundation also decreased. Reducing the loads on foundations can significantly reduce the cost of their construction. It was also found that a change in the type of section can affect the changing of the direction of movement of the building's vibration forms. The results of the study demonstrate the possibility of optimising structural solutions by changing the geometry of columns, which not only saves resources but also ensures reliable operation of buildings.