Simplified method for time-dependent effects in statically indeterminate concrete bridges with connected precast beams

Nowadays, structural analysis programs are available to deal with continuous precast bridges with evolutive cross sections, but they hardly allow for a real control of the process with a full awareness of what consequences have the variation of the inputs in the final stress distribution. The present paper presents a simplified method as an improvement of the transformed section method with age-adjusted effective modulus for composite sections consisting of precast prestressed beams and a top concrete slab. The proposed method is verified by comparison with the comprehensive step-by-step method. The results are accurate not only in terms of stresses but also delayed curvatures, which allows its application, to all types of continuous bridges with staged construction process. The method is also applied to the calculation of a complex real bridge and the comparison of the results with the methods used in practice, as well as the criteria endorsed by experience.

Automated summary

This paper presents an improved method for structural analysis of continuous precast bridges and verifies it through comparison with existing methods. The results demonstrate that the proposed method accurately calculates both stress distribution and delayed curvatures, making it applicable to various types of continuous bridges with staged construction.