Prestressed bridge flexural design check (AASHTO LRFD 2007)
Handling of hyperstatic moments
The flexural design check for prestressed-concrete box-girder bridge superstructures fully accounts for secondary effects from prestress-tendon forces. Primary prestress forces are removed and demands automatically include secondary forces. Hyperstatic load cases need not be included in design combinations. Tendons must be modeled as elements for the flexural design check.
Users should create load combinations with prestress loading. Primary forces are calculated through subtraction of tendon force from demand. Additional concrete forces are either secondary or imposed.