The efficient design of prestressed concrete girders typically requires varying the strand eccentricity along the length of the member or limiting the strand force at transfer. Prestressed concrete girders are usually fabricated, stored, transported, and initially installed as simply-supported segments. For a simply supported girder with straight strands, the large eccentricity between the strand and the center of gravity of section helps reduce tension caused by bending moment and possible cracking at midspan at the service level. However, excessive flexural tensile stresses may develop at the top of the girder segments near the ends, where counteracting flexural stresses due to self-weight are minimal. In such cases, it is helpful to use draped tendons.
IDEA StatiCa Team