Analysis Theory of Unbonded Prestressed Concrete Continuous Beams[J]. Journal of Civil and Environmental Engineering, 2000, 22(1): 5-10. DOI: 10.11835/j.issn.1674-4764.2000.01.002.
the energy method has been used to study the change of the secondary moment of unbonded prestressed concrete continuous beams and it has been contrasted with bonded prestressed beams. The question
whether the secondary moment changes or not while loading
was answered. It shows that the primary secondary moment does not change when increment method is adopted to study the beams
but the total secondary moment will change while the force in prestressed reinforcement changes.