What fixities could you add?
Most structures are fixed along the bottom or side edges. In your model, you should fix at least one node in both the X and Y directions and another node in the Y-direction.How are real dams fixed?
Hopefully, the base of a dam will be connected to the rock underneath it so that it won't move in any direction. To model this in a simulation, you could fix the whole bottom edge of your dam. To do this, click on all the points along the bottom edge of your structure.
In the applet itself, the button is called Attach.
| On the simple gravity dam, there are small red blocks on all the points along the bottom edge. This is where it has been fixed in both the X and Y directions. |