MODELLIND OF STRESS STREIN STATE OF COMPACT STEEL BEAM STRUCTURES FOR RATIONAL REINFORCEMENT OF EMERGENCY REINFORCED CONCRETE RIBBED ROOF SLABS

Abstract

In the paper have been considered solving of important scientific and practical problem of modeling the stress-strain state of multi-element beam structures of emergency reinforcement of precast reinforced concrete ribbed slabs on the example of a real office building of the "Vinnytsia Innovation and Technology Park", which is being designed on the territory of the former production premises of the "Krystal" plant. These covering slabs, which serve to support the layers of a flat roof, have suffered significant force damage during long-term operation, that is, they have all the signs of reaching the first and second groups of limit states. But their replacement, due to late detection of defects and economic factors, was virtually impossible. In addition, have been formulated an additional requirement for design solutions regarding the minimum protrusion (bulging) of reinforcement structures from under the slab clearance to ensure the design construction height of the ceiling of the premises under the emergency slabs by the request of the project architect. Therefore, during the above-mentioned scientific and practical works, there was a need to develop a non-standard reinforcement method, namely, compact beam structures with the complete exclusion of defective reinforced concrete floor slabs from the work. Have been offered a reinforcement solution in the form of a system of low-height cross-section beams, often supported from the bending plane by bent profiles. The authors of the scientific research also solved the difficult task of ensuring the inclusion of the offered multi-element system of compact steel reinforcement beams in the overall operation of the load-bearing structures of the coating by temporarily leveling and unloading the emergency structures with jacking systems and wedging all elements. Have been developed a rational technological sequence of work, in which special attention was paid to safety issues in general and fire safety of reinforced structures in particular. Have been successfully implemented in practice the constructive and technological proposals presented in the paper.