One of the significant factors determining the safety of a building structure is the compliance of the adopted calculation model with the actual nature of the work, confirmed by experimental studies. An engineering method is proposed for calculating the strength of reinforced concrete beams (with a relative shear span from 2 to 4) in the zone of action of transverse forces, which allows taking into account the combined influence of moment, transverse and longitudinal forces in the design sections. The possibility of presenting a calculation model of a reinforced concrete beam in the form of a double-hinged arch with a tie is considered. The operation of a reinforced concrete beam is modeled in the form of a spacer system with a horizontal stretched belt (longitudinal reinforcement) and a compressed concrete arch of a curved outline. This model: reflects the physical operation of the structure; provides a unified approach to calculating the strength and crack resistance of normal and inclined sections of bendable reinforced concrete elements; allows you to take into account the combined action of transverse forces and moments in an inclined section; harmonizes existing methods for assessing the strength of bending reinforced concrete elements with a relative shear span of up to 1 and more than 3; ensures maximum savings in concrete and reinforcement materials due to rational use at a given level of reliability and durability. The obtained calculated dependencies for assessing the strength of reinforced concrete beams without transverse reinforcement under the action of transverse forces are consistent with experimental and theoretical studies and are based on generally accepted principles of structural mechanics.