Staged Tensioning Control of Precast Box Girder Prestressing Based on Orthogonal Experimental Analysis

Abstract

In the field of bridge assembly construction, longer girder storage periods and high temperature and humidity vaporization environments may lead to increased prestress losses in box girders at later stages. In order to reduce the prestressing loss of prefabricated box girders, this paper relies on the actual engineering, through the orthogonal experimental design method, adopts the L16 orthogonal table for the initial tensioning condition of prefabricated box girders, and simulates Maximum stresses of box girders in different working conditions by utilizing the finite element software ABAQUS. The main factors affecting the box girder stresses were determined by polar analysis and one-way ANOVA. The results of the study show that the prestressing efficiency of the box girder can be improved by symmetrically tensioning 8 or 10 steel bundles when the concrete strength reaches 70% or 75% while meeting the concrete strength requirements.