Camber analysis and design of continuous prestressed concrete beams

c. , c. -c for bottom (top) fibers, c. ', c.' -c for composite sections, c.g.c.-Center of gravity of concrete section, c.g.c' -Composite sections; c.g.c. for composite sections, c.g.s.-Center of gravity of steel, e. e,, ep -Steel eccentricities.F -Total effective prestressing force after losses.FQ -Total prestressing force at transfer, f ' -Compressive strength of concrete, fxf fu -Fiber stress in top (bottom) fibers, f.', f. ' -Tensile stress in top (bottom) fibers, h -Depth of precast beam.I -Moment of inertia.r -Composite sections; I for composite sections, k. , k^ -Kern distance from c.g.c. for top (bottom).M -Moment acting on composite section.M ' -Negative moment acting on composite section.Mp -Girder load moment.M -Moment on precast portion of composite section.vi vil M ' -Negative moment on precast section.Mj -Moment due to total load.Mj Negative " ^°^^^ negative moment.m. , m. -Ratio of section moduli of precast portion to composite section for bottom (top) fiber, r -Radius of gyration, x-S, -Length of left overhang, beam with two supports.Sp -Distance between supports.S-, -Length of right overhang, beam with two supports.