Flexural Response of Reinforced Concrete Beam on Elastic Foundation under Vertical Load and Bending Moment: Review of Existing Methods and Proposed New Method

This work examined the behavior of a RC beam on a soil foundation subject to concentrated vertical loads and bending moment in both the elastic and the plastic phases. Some of the simplified methods for hand calculations available in the literature, which are useful for preliminary design of foundation structures, were presented and compared. A simplified plastic calculation method is proposed considering limit cases of partial or full plasticization of the soil and the formation of plastic hinges in the beam with elastic or plasticized soil. The proposed method had good agreement with other methods presented in the literature. The proposed method provides a simple calculation tool useful for the calculation of the foundation’s bearing capacity and for verifying the overstrength of the soil–foundation system. The plastic resources of the soil–foundation complex depend not only on the characteristics of the soil, such as cohesion and friction angle, but also on the geometrical and mechanical characteristics of the RC beam and the vertical load characteristics (intensity and eccentricity). It also was shown that the maximum ratio of longitudinal steel bars should be determined to ensure strength hierarchy. with plasticization of RC beams before soil plasticization.