A post$-$tensioned beam having the cross section shown in Fig. P$4\mathrm{.}6$ will be used as a single$-$lane access ramp of $120-$ft span. The flat, upper flange surface will serve as roadway and walk. The service live load providing the basis for design is $200$ psf assumed uniformly distributed over the full width of flange and full span of girder. The weight of curbs $($non$-$structural$)$ and railings is $100$ plf of span. Required clearances and visual factors limit the total depth to $66$ in$.,$ and a web width of $14$ in$.$ is selected anticipating the need for placement of stirrups for shear and torsion $($not a part of the present design problem$),$ as well as prestressed and non$-$prestressed flexural steel. The average depth of flange, governed by transverse bending and shear requirements, will be $7$ in$.$ Design the girder for flexure, using partial prestressing, and incorporating the design requirement for a balanced load state when full dead load acts. Non$-$prestressed reinforcing bars may be used if required to provide the needed strength. Stresses in the member in the initial stage and full service load stage should be checked, but need not meet the restrictions of the ACI Code. Check the width of cracks, if any, at full service load, using either of the methods of Section $4\mathrm{.}8.$ Concrete strengths are f$=6,000$ psi and f $4,500$ psi. Standard Grade $270$ strands will be used for post$-$tensioning $($e$.$g$.,$ Freyssinet system as shown in Appen$-$ dix B$).$ Grade $60$ rebars may be used also. Time$-$dependent losses are estimated at $20$ percent of the initial prestress force.FIGURE P$4\mathrm{.}6$