DESIGN OF TRANSITION JUNCTIONS OF SILOS’ CONICAL HOPPERS ACCORDING TO EUROPEAN STANDARD EUROCODE

Abstract

Problem statement. Today, the food security of the world is one of the main issues for the political, economic and scientific community, and the recent crisis with the export of Ukrainian grain only intensifies the urgency of the problem. The important part of this issue is creation of reliable and safe grain storage silos. An analysis of recent accidents in silos, especially with conical hoppers, revealed a range of imperfections in outdated regulatory practices that Ukraine inherited from the Soviet building norm system. A limited list of agricultural crops, ignoring the statistical spread of their physical and mechanical characteristics, not differentiating between the stress-strain state for filling and discharge silos, the absolute absence of guidelines and recommendations for the design of principal connections - this is a far from complete list of shortcomings and omissions of outdated Soviet standards. With the entry into force of the new Ukrainian norm DBN V.2.6-221:2021 “Designs of steel silos with a corrugated wall for grain”, the situation should have changed. Firstly, the new standards take into account the world experience in design, construction and fabrication of silos, and secondly, they have a direct and legitimate reference to the necessary standards of the Eurocode system, in which a modern engineer can find answers to a wide range of practical questions. Unfortunately, the introduction of this, without exaggeration, modern and extremely important standard into construction practice is constantly ignored. On the one hand, this is due to the unwillingness of Ukrainian manufacturers to switch to new European and more rigid requirements for reliability and safety, on the other hand, the fear of Ukrainian engineers in front of the complex and extensive Eurocode standardization system. The purpose of the article (ignoring the financial commercialism of individual silo manufacturers) is explain to domestic designers a few provisions of the new DBN V.2.6-221:2021 related to the design of silos with a conical hopper. In particular, the design of one of the very important units at the point of transition of the cylindrical part of the silo to the conical hopper. Methodology. For this, the general ideology and methodology of the limit state method, implemented in the Eurocode standards through the system of partial reliability factors, as well as classical methods of structural mechanics, which are still not reflected in the system of building regulation of modern Ukraine, are used. Results. As a result, clear recommendations for the design of the transition junction of silos with a conical hopper in accordance with Eurocode and DBN V.2.6-221:2021, as well as clarification of “special” points that are not properly covered in both regulations. Conclusion. The recommendations and explanations given in the article, firstly, accelerate the introduction of the new DBN V.2.6-221:2021 into engineering practice, which is harmonized with the Eurocode system, and secondly, allow to achieve more reliable and safe design solutions in the field of silos fabrication, in thirdly, they deactivate the chronic design fear of Ukrainian engineer before the European school of building standards.