The influence of the state of inter-slab joints of floors on the deformability of multi-story braced frames
Abstract
The influence of the state of inter-slab joints of floors on the deformability of multi-story braced frames
Incoming article date: 05.12.2025This article presents a practical approach to the design of precast concrete frame buildings based on a developed methodology for accounting for the flexibility of joints between floor and roof elements, using a plate-and-rod model of a floor fragment. For two types of braced frames (with symmetrical and asymmetrical stiffener arrangements), an analysis of quantitative indicators of deformability and relative forces is presented, with reduction factors applied to the integral rigidity of the precast floor in its plane, obtained using the proposed methodology. This analysis compares this approach to the classical approach to designing precast frames, taking into account the rigidity of monolithic floors. The results of the calculation of frames using the proposed method show that with a decrease in the rigidity of the floors (reducing to equivalent rigidity, taking into account the flexibility of the seams in the joints of the floors), the vertical forces in the columns from horizontal loads decrease, and the moments in the stiffening diaphragms increase, that is, in the frame structures, both reserves and deficiencies in the bearing capacity can be identified, which is especially important during the inspection and subsequent reconstruction of buildings with the structural system under consideration.
Keywords: multi-story frame structural system, precast floor, flexibility, horizontal load, joint, rod model, equivalent stiffness coefficient