Warping Ribs - lines when I curve array


I am new with rhino and grasshopper. we are trying to do a bridge on grasshopper, we have the central line, and surface itself. What we need to do is put ribs in every 2 meters (could be variable) below the deck. But the problem is that the deck we have is sloping, its not flat. When i try this script on a flat curve, it is working as we want, but as soon as i define a curve that is sloping, then the rips starts to twist around. ( I use curve array to array my arc ((ribs)), i think that is what causes the problem.
You can see the screenshots, we will be really glad with your help. Thanks in advance.

welcome to the forum. In order to be helped you better read that :

In résumé : we will be happy to have something more usable than a screenshot. Why not a script with data internalized (surface of the bridge) or in a 3dm.