On the basis of the second variant of the Timoshenko theory with the involvement of the idea of the steps method in time at discrete points in time the task is formulated for inelastic deformation of the longitudinal-reinforced beams-walls considering their weakened resistance to lateral shear. Mechanical behavior of phase materials of beams describes nonlinear-hereditary Rabotnov theory of creep. Mechanical behavior of simply supported beams is investigated; it is found that the application of the classical Bernoulli theory to the calculation of inelastic bending relatively high reinforced beams leads to the prediction of unreasonably understated their compliance. The calculations have demonstrated the presence in a binder of such beams the significant inelastic deformations of transverse shears, which actively develop over time and which accounting is required