Effect of Capacity Hyperstatic Prestressing Moments and the Carrying Capacity
of Continuous Beams
Appears on pages(s):
continuous beams; elastic analysis; loads (forces); moment;plastic analysis; prestressed concrete; prestressing steels; structural analysis.
The effect of hyperstatic prestressing moments and the carrying capacity of continuous beams under both proportional and variable loading is investigated. The magnitude of the prestressing force near the ultimate load and its effects are still a controversial subject that this paper will try to clarify. The elastic behavior is first reviewed, including linear tendon transformation. The ultimate carrying capacity is evaluated by plastic analysis. Use of the shakedown theorem is made for variable loads to prevent incremental collapse. This procedure is particularly attractive for design applications because it permits an elastic analysis of all loading situations and the use of the law of superposition. The Appendix contains a demonstrative example.