Stability design of long precast concrete beams

& This paper presents the equations needed for design engineers to check the stability of precast concrete beams when simply supported, during transportation, when being lifted and while sitting on flexible bearings. It shows how the critical loads can be determined and how estimates can be made of the eAect of imperfections both in the beam itself and in the degree of levelness of its supports. It shows how the stresses induced by second-order eAects in imperfect beams can be determined. Various examples are given of the method in use.