Shear check is based on AASHTO Article 5.8.6, entitled Shear and torsion for segmental box girder bridges. The shear design-check request provides the following results:

• Controlling demand-capacity ratio

• Shear rebar area and length

• Torsion rebar area and length

• Shear and torsion area and length

• Longitudinal rebar area (shear causes tension in longitudinal reinforcement - see AASHTO LRFD 2007, C5.8.3.5)

Web shear force and resistance

Shear force and shear resistance are idealized to act along web height. Capacity is proportional to area. Components relate forces in the reference frame to those within an inclined web. Web force is found by magnifying the vertical force by 1/cos(α). Similarly, vertical force is derived by reducing web force by cos(α). Given this relationship, an element web most effectively resists vertical shear when oriented vertically.