We have an existing column which is 250x250mm to which we are introducing a steel beam with an end plate. The loading at the anchors is not the largest, however the software highlights a edge breakout failure in the concrete. The load acts along the length of the column and is just applying a shear force. We have tried what we can to improve the utilisation however a failure still occurs. An explanation of the failure and any guidance on how to solve this would be extremely useful.
Thanks for your question, you mention you are fixing to a column 250mm sq which has an edge distance of 2640mm in the direction of the shear yet the connection is failing. Now the software is following EC2 Pt 4 and when you input a dimension then that edge has to be verified, it does not matter whether you select 100mm or 15000mm it becomes controlling.
The reason for this, in the case of 3 or more edges then the 'large edge' is reduced to c'1 . Please refer to the extract from EC2 PT 4 Figure 7.16 .
Now it's perfectly reasonable for you to look at your column and considered if the column runs into a foundation slab, pile cap etc and that the bottom edge is actually continuous / fully restrained. You are then at liberty, to select the infinity option to remove this 3rd edge to produce a solution.
