What might the cracks look like?

The cracks you draw will be green. Think about where your loads are when you are adding your cracks. Will your loads make the cracks grow?

Here the gravity dam is cracked in two places. Note that the crack on the left edge will be forced open by the water load also on that edge. The other crack may or may not grow. Also, note that cracks must start on the outside edges of your structure.