[This article belongs to Volume - 36, Issue - 05]

Influence of Arrangement of Tie Members on Overall Stability of Scaffolds

The purpose of this paper is to show the influence of incorrect scaffolding foundations on the stress in their elements. Static stress analysis was performed for exemplary steel façade scaffolding. The scaffolding was formed using the Plettac 70 system and was composed of 16 modules and 13 working levels. The total dimensions of the scaffolding were 45.0 × 26.36 × 0.74 m. The scaffolding was set up partly on concrete and partly on a created ground classified as coarse sand with discontinuous graining. The boundary conditions modelling the foundation considered the heterogeneity of the ground both along the scaffolding and in the direction perpendicular to the façade. The effect of uneven subsidence on the scaffolding frames was checked, adopting a constant stiffness of 3500 kN/m in half of the supports, while in the rest of them the stiffness varied from 35 to 3500 kN/m. Due to additional bending moments, normal stresses in stands and transoms of the frames increased. Incorrect scaffolding foundation has the greatest negative effect on normal forces in anchors and bracings. Because these elements are responsible for the stability of the scaffolding, their damage may result in scaffolding failure and would certainly lead to a reduction of the values of free vibration frequencies, thus resulting in the discomfort of the workers on the scaffolding and a lack of safety.