If the spikes do not go all the way through the tie, the pointed end can slowly be forced out, just as frost heave pushes on the end of a stake not below the frost line.
SS won't rust but they work out easily. Steel will rust, and not come loose, but the heads will rust off like RJ says. Longer spikes may help.
So far all the suggestions are right, but I think the only workable one is longer spikes.
Regards, Greg