ABSTRACT
The smaller of these two values gives the greatest permissible value of es at any section. If Mt = 0 (for example, at the supports of simply-supported beams), then
' eb \ Pt I M p t + 1
In theory an upper limit for es can also be obtained. In practice it is never necessary to deflect cables so that the centroid of the prestressing force is higher than that of the beam, and this can therefore be taken as the upper limit. If the effective eccentricity of the prestressing force is between these two limits the permissible stresses at transfer are not exceeded. The method of calculation for a uniform beam is shown in the following example.
