Preventing progressive collapse of flat plate structures with an irregular layout of structural integrity reinforcement.

摘要

To investigate the post-punching shear resisting mechanism of slab-column connections having an irregular layout of structural integrity steel, two test specimens were designed, constructed and tested. The aim of the research program is to determine the appropriateness of the CSA A23.3-04 code provision which assume that the post-punching shear resistance is a function of the total area of bottom steel. The first of two test specimens experienced significant tilting which may have reduced the post-punching resistance of the slab-column connection, however, the second test specimen was able to resist the expected post-punching load as required by the CSA code. The slabs were designed with 150% of the required structural integrity steel, a ratio of three to one for area of structural integrity steel provided in each span direction, detailing the minimum slab thickness required for the span length between columns, and provisions for high design live loads. These factors likely reduce the post-punching resistance of slab-column connections, however, the details specified using the code were adequate.