Yield line analysis
Yield line design is a well-founded method of designing reinforced concrete slabs. It uses yield line theory to investigate failure mechanisms at the ultimate limit state. It is a robust and proven design technique that challenges designers to use judgement; once grasped it is an exceedingly powerful tool.
The European Concrete Building Project at Cardington, which tested a variety of methods of designing flat slabs. It concluded that “yield line was easily the best opportunity available to the concrete frame industry” to provide best value in floor design and construction. In particular it found that yield line design leads to slabs that are quick and easy to design and to construct. The resulting slabs are thin and have low amounts of reinforcement in very regular arrangements. They are therefore easy to detail and fix. Above all Yield Line design generates very economic concrete slabs. Practical yield line design from the Reinforced Concrete Council explains how the method may be used in the design of economic concrete flat slabs and raft foundations. It also includes worked examples and case studies, bringing together theory and practice.