Combined Design of a Long-Span Building

design of a saddle-shaped building (structure) on a rectangular or oval plan has been developed and calculated. This design consists of parallel arches in the direction of the object's width, with a variable lift that increases towards the ends of the object, and a series of parallel rigid cables in the direction of the object's length, which are connected to the arches at their intersection points, forming a saddle-shaped spatial large-span roof. The arches are made using tubular profiles, have a through section of 2 lower (internal) belts, 1 upper (external) belt filled with concrete, and a lattice. The arches at the ends of the object have an outward slope and are reinforced with half-timbered posts. The rigid cables are made of metal pre-stressed I-beams. The upper (external) belt of the end arches is fixed with pre-stressed ties, and the supporting parts of the arches are connected with pre-stressed ties. The proposed innovative design has been calculated, and the reduction in material consumption and increase in rigidity have been determined. Practical significance: the effectiveness of the use of combined steel-concrete structures in the frames of large-span buildings is established. The proposed building frame design has a reduced steel consumption of 16 % while increasing the rigidity by 8 % in comparison with the known designs of metal frames of large-span buildings. The combined design of the saddle-shaped roof can be used in railway stations, canopies, quays, and other transport facilities.