TEST RESULT - Mines will explode a number of times within the same turn
PIC 1 - A column of T-34s are lined up ready to charge through the gap on 'Fast'. They can't see the buried German AT-mine I've sown there..
PIC 2 - They begin racing through but one of the leading pair is immediately immobd, but his mate gets clean through. The mine icon now appears on map, the other 18 tanks see it and jam on their brakes and begin concertina-ing and re-plotting...
PIC 3 - I cancel their auto-plot orders, get them back into column formation and charge them through the gap again. (Interestingly, none of them jam their brakes on again even though they can see the icon, they follow orders and try to go straight through, 12 of the 18 get through unscathed)..
PIC 4 - These are the 6 that didn't get through. (one other is the one immobd in pic 1)
Remember, all these 6 were blown up
in the same movement phase, confirming minefields are not limited to just one detonation per phase.
But as Mad Russian pointed out earlier, the chances of detonation do seem to lessen each time, as if the field is slowly depleting after each blast..
CONCLUSION - Charging a whole bunch through in one turn won't save them from getting blown up, you could lose 1 in every 3 tanks as in the above tests, although I daresay the figure randomly fluctuates from game to game.
I suppose the only tactical situation in which you deliberately want to drive your tanks through mines is if there's absolutely no alternative like clearing them with engineers, or bypassing them..