I think 'ties' is sufficient here, since we don't know preciely what form they take. What isn't clear to me, and I don't know if your wider context explains it or not, is wether or not these 'tirants' are part of the gabions themselves — as their width is mentioned, it certianly could make sense, since gabions that wide could tend to 'bulge' if not held tightly together. But it is also possible they mean ties that are fitted between rows of gabions; either way, I don't think that necessarily changes the translation — though if they were within the gabions themselves, it's interesting to speculate just how many ties there would be within any one gabion, to justify the term 'lit', which surely suggests several? Unless, of course, they mean one per gabion, but forming a 'lit' once several gabions are placed side by side...

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Note added at 1 day 4 hrs (2018-10-08 04:53:15 GMT)
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In the light of Asker's added context, I think we can now fairly certainly tell that:
1) These are not 'rods', but some kind of wire being used as a 'tie'
2) They do indeed seem to be tying together the front and back of the actual gabions themselves (to prevent bulging).