Modern Designs of Arch Load-Bearing Systems of Public Buildings

Purpose. The main purpose of the publication is a comparative analysis of the structural variants of the load-bearing arch system for public buildings with insulated covering. The relevance of the work is associated with the modern trend of creating public buildings of various types without internal intermediate supports. The subject of the work is also due to the desire to apply for this purpose known arch systems, which allow to significantly improve the architectural and aesthetic indicators of the building. Methodology. To achieve this goal, a project of a grocery and non-food store located in the Lviv region of Ukraine was considered. A circular steel arches with a span of 17.5 m and a sweep angle of 90 º is the basis of its supporting frame. During the analysis, a comparison of different types of arch cross-sections was performed – welded and rolled I-beam, welded rectangular pipe and seamless round pipe. The finite element method based on the SCAD design and computing complex (Ukraine) was used for the research. Findings. The comparative analysis made it possible to determine the geometry of the most rational constructive solution for the given conditions in the form of an I-beam welded cross-section. All other types of cross-sections considered have a lower level of efficiency and manufacturability of manufacture. Additionally, the main «weak» points of such a cross-section were identified and recommendations were given for their elimination. Originality. It consists in the fact that the comparative analysis made it possible to assess the possibility of using an arched load-bearing system as a load-bearing element of an unsupported frame of a public commercial building with an insulated roof structure. Practical value. It consists in the fact that a structural solution of a small-span steel arch in the form of a welded I-beam has been developed and proposed for practical implementation, which turns out to be approximately 1.5 times less material-intensive than possible analogues. The nature of the distribution of the material efficiency coefficient for given construction conditions has also been obtained.