Numerical Investigation on the Influence of Shoring Stiffness on Slab Deflection with Consideration of Construction Phase Loading

The construction phase of reinforced concrete buildings is critical, as temporary loads during shoring and reshoring can induce deflections that impact long-term serviceability. Traditional methods for evaluating these loads rely on assumptions of infinite shoring stiffness and uniform load distribution, which can lead to underestimation of deflections, especially when concrete creep is not considered. This research proposes a finite element modeling (FEM) process, integrating shoring stiffness, time-dependent concrete properties and concrete creep to simulate the load-deflection behavior of multi-story reinforced concrete buildings from the construction phase to the application of the service load. The aim is to study the influence of shoring system stiffness on load distribution and slab deflection. The proposed methodology, implemented in a standard FEM software, is then applied on a typical building for construction phase schemes including one level of shore and one, two and three levels of reshoring. The influence of stiffness variations is studied. It was found that accounting for the stiffness of shoring systems is essential for reliable assessment of slab deflections during the construction phase.