Analysis of Externally Prestressed Segmental Bridges (EPSBs) still needs more effort. At an earlier stage, an experimental investigation was carried out by the authors. The experimental investigation was consisted of ten specimens having different joint configurations, and it was divided into two phases. The first phase contains five specimens constructed with multiple small-amplitude shear keys in accordance with AASHTO. The parameters selected for the first phase were different levels of prestressing force in tendons as well as different levels of applied torsion. The second phase contained four segmental specimens and a monolithic one. The joints in the second phase took four forms: multiple small-amplitude shear keys, large-reinforced shear key, steel shear connectors, and UHP–SHCC joint connecting the tension flange. This paper proposed an analytical procedure to calculate the full prestressing load and partial prestressing load based on the forces' equilibrium. Skew Bending Model that inspected by Huan and Liu, 2006, to calculate the load-carrying capacity for segmental beams with internal unbonded tendons subjected to combined bending, shear, and torsion modified to calculate the ultimate capacity of EPSBs and gave satisfactory agreement with the experimental results.