Deflections must always be considered in slab design to meet the serviceability criteria applicable to concrete floor systems. While there are several ways to determine and calculate slab deflections, Tekla Structural Designer is arguably the most capable software solution available.
Kenny Arnott, Principal Structural Consultant at Trimble Solutions (UK) Ltd explains why.
There can be many requirements to consider when evaluating concrete floor deflections: the deflection (slope) of a slab must not be noticeable to occupants, and deflections must not cause damage to attached partitions, sheathing, and other critical non-structural elements. The most basic requirements are stipulated in the design codes, but very often more onerous project-specific limits will apply.
Flat slabs" (concrete slabs supported directly on columns/ walls without the stiffening effect of beams) offer the greatest concern and challenges in this area. Although buildings have been constructed using flat slabs and columns for many years, serviceability compliance (deflections) was traditionally evaluated by hand, without the aid of computers. However, this traditional method relied heavily on regularity, standard conditions and limits to keep design complexity to a minimum. As structures became more individual and complex, more innovative solutions were required to perform the necessary analysis.
