Research on “zero-damage” control technology for box girder of prestressed concrete

Abstract

When adopting the incremental launching method for bridge construction, there occurs alternating positive and negative bending moments or deformation of curved bridges. The prestress and devices, such as slideways and position-limit, may cause cracking of box girders during the incremental launch. To ensure zero damage in this process, an in-depth study was conducted from the perspective of tensioning technique and vibration technique of concrete in special parts, using Midas Civil, a Finite Element Analysis software, to model and conduct a force analysis, and finally selecting partial tension-induced schemes. Meanwhile, a series of measures were taken, such as adding fabric holes and holes of vibrating, customizing steel bottom, and setting differential settlement to control the quality of concrete, which can create favorable conditions for zero damage of box girder during the incremental launch.