Assessment of Shoring System for Safety of Elevated Slab Formwork Using Nested Factor Designs

The objective of this paper is to present the results of a statistical analysis for the performance of the shore slope to determine the stability of metal single post shores in high-clearance elevated slab formwork. Considering the potential collapse of elevated slab formwork during concrete placement due to deficiencies in regular vertical shores, the assessment of shoring system for safety is significant. There is no specified slope tolerance regulation for shoring systems since one recognizes all post shores being plumb from a common sense standpoint as well as the existing regulations. Therefore, it is necessary to assess the accuracy of the shoring installation. In doing so, nested factor designs have been conducted to compare the stability of low-clearance shoring systems to that of high-clearance shoring systems, using shore slope data measured on actual construction sites. The average error for the shore slope was 3.156 degrees. Experimental results are inconclusive because there is no difference among the averages of high-clearance/low-clearance projects for the shore slope. However, it is conclusive that there is a variation among the locations within high-clearance/low-clearance projects. The results of the statistical analysis indicate that the accurate installation of the shore is an important factor for the shoring safety during construction in high-clearance concrete buildings. It is strongly suggested that the error in the single post shore slope be considered when conducting a structural analysis for shoring systems in high-clearance elevated slab formwork construction.