Research On The Design Principles Of Vertically Tensioned Prestressed Concrete Beams

The vertically tensioned prestressed concrete (VTPC) has technical and economic advantages in its practical scope. At present, a large number of research achievements about theories and applications have been provided, yet the system of the design theory has not been formed. Based on the extant results, this thesis focuses on the design principle of VTPC beams and makes the following researches:1. On the basis of the discussions about the global structure and construction technology of the VTPC beams, the methods used to calculate the stretching control and the loss of the prestress are presented. The methods to analysis the section stresses during the construction and service stages are respectively provided for the bond anchorage,inclined and flat straight parts of a VTPC beam.2. According to the experimental results of 10 VTPC beams, the shear and flexure resistances of the VTPC beams are studied. The structural measures are provided to assure the mechsnical performances of VTPC beams.3. Based on the fatigue test results of 4 beams, the fatigue shear and flexure performances of VTPC beams are studied. The tests show that VTPC beams can work well under fatigue loading while some suitable structural measures are used in the beams.4. On the basis of the tested results of 32 pre-post-casting samples, the interface shear performances are studied.The calculation methods and structural measures are suggested for the interface shear design of the VTPC beams.