Irregular flat slabs designed according to structural membrane approach

Abstract

In the construction industry, the need for flat slabs supported on columns in an irregular layout is rising. Design methods validated by experimental evidence for flat slabs supported on non-rectangular grid are, however, scarce. To fill this vacuum, two irregular flat slabs were tested at Nanyang Technological University. Those slabs, however, failed at almost twice the design ultimate load, showing the need for more work. In this paper, existing design methods based on lower bound approach are reviewed. Gurley's bimoment concepts are used to check the validity of zero twisting assumption in some of these methods. Also, experimental details of the nine flat slab panels, supported on non-rectangular grid, designed using the structural membrane approach and tested at Cambridge University Engineering Department are provided. Based on the observations, some suggestions are made for practical application of the structural membrane approach to design flat slabs on non-rectangular column grid.