Design Of Three Dimensions Prestressed Structure With Curved Beams

The requirement to construction is no longer confined to functions of use and economy behavior with the development of society, while the requirement to beauty is more and more considered. So space curved beams are more and more used in today's civil engineering. Prestressed concrete curved beams are used often in large span structures. The curved girder are also used in large-scale exhibition center and stadium.In comparison with straight beam, the prestressed concrete curved beam have deformation in the plane(axial, shearing, bending) and deformation out of the plane(including torsion). Thus, the design of PC curved beam is very complicated. The element stiffness matrix of the space curved beam are derived according to the theory of mechanics, and the various equivalent node load matrix are derived in terms of deformation harmony relationship of the element.For curved beam, the prestress should be added to beam to balance bending moment and torsional moment of dead load first, than balance torsional moment, so synthesis prestressed tendons are derived; enough common steel could be designed to offset the internal force of applying load and the secondary moment of prestress.