Strain monitoring of the Super long prestressed foundation beam

The exhibition hall of Hefei lakeside international convention center is shaped surface space grid and tube truss structure.in order to balance the horizontal force caused by the long span steel roof, the foundation beam with a span of 76.3m adopts bonded prestressed concrete beam, which is the longest span in China. In order to meet the design requirements to ensure the prestressed beams, using strain monitoring system to track and monitor the Strain rate of the prestressed beams and the steel strand. The results show that: For the similar design of prestressed concrete beams in this project, the need to consider calculating the Bearing capacity of the beam and crack computation of the tension before imposing beams prestressed tension; ordinary one end of tensioning prestressed concrete beam method is not suitable for the long prestressed girder which must be used at both ends of tension; the rule of the stress losses is not the same as the conventional prestressed concrete beam, it is necessary to revise the formula to adapt for calculating such long prestressed beams.