The construction of public buildings from a metal frame is always associated with the search for a rational constructive solution that meets not only the dependability requirements, safety, but also architectural and design solutions. Often, the solution to the problem of rationalization of roof construction in public buildings is the use of arched combined systems, since such systems have a number of advantages over simple arches: the survivability of combined systems is higher than simple ones, the possibility of creating complex, architecturally expressive spatial structures, lower material consumption, high load-carrying ability with relatively low weight, etc. The aim of the research is to find a rational construction solution for two arch-cable systems (Hud type system and Radial type system) by comparing in terms of the minimum internal forces, displacements and metal intensity at different ratios of the arch boom and span. Based on the calculation results in the Lira SAPR 2020 software, the most unfavorable loads combinations were determined, deformation schemes of arch systems, displacements, moments and forces were obtained, sections of arches and ties were selected. From ten arched structures of two types considered with different ratios of arch boom to span, the Hub type system with the ratio of arch boom to span f/L = 1/3 and Radial type system with the ratio of boom to span f/L = 1/4 showed the best result in terms of efficient operation and metal intensity.
Keywords: combined systems, arch-cable constructions, simulation of prestress, hub type s