A tensioning control method for stay cables with super large tonnage cable force

Abstract

PurposeEffectively solving the large tonnage cable in the construction process due to the tensioning method of the inclined cable often appears in the overall cable force and the design value of the deviation is large, cable internal strand force is not uniform, the main girder stress exceeds the limit of the problem affecting the safety of the structure.Design/methodology/approachIn this study, the finite element method and theoretical analysis method are utilized to propose a construction control method of tensioning the whole bunch of diagonal cables in two parts according to the deformation coordination relationship between the main girder and the diagonal cables. This methodology was implemented during the actual construction of the PAIRA Bridge in Bangladesh.FindingsTests conducted on cable-stayed bridges using this controlled tensioning method demonstrate that the measured cable strength of a single strand exhibits an error of less than 0.15% compared to the design target cable strength. The deviation between the measured and designed cable forces ranges from 0.16% to 0.27%. Furthermore, no tensile stress is observed in both the top plate and bottom plate of the root section of the main girder, indicating a state of full-section compression throughout the entire construction process.Originality/valueThrough the comparison with the test value, it can be proved that the whole bunch of diagonal cable tensioned in two parts of the construction control method proposed in this paper can make the internal strand force more uniform, to meet the precision requirements of the site construction, to protect the safety of the bridge construction process. The method proposed in this paper is highly accurate, easy to calculate, and has a high value of popularization and application.

Algorithms for Computer-Based Calculation of Individual Strand Tensioning in the Stay Cables of Cable-Stayed Bridges

“…In defining the tensioning program, besides the aforementioned considerations, the applied cable system and the equipment available to the contractor are highly relevant. Given the time and labor intensiveness of the procedures of optimizing cable tensioning during installation and construction, control becomes very important [22]. The primary objective is to minimize repetitive cable tensioning and achieve the targeted cable force according to the design specifications, thereby eliminating the necessity for final cable force adjustments [23].…”