can someone advise please how to disable this trap, ive tried bow and arrow but no effect

Fire a spell at it, arrows also work if you aim just right.
You can also pick something up and throw it on the trap or use telekinesis.

i have tried spells and arrows, nothing works, ive used unrelenting force and moved the soul gem but it does no good

I thought it was a rune trap, but do you mean those traps with the soul gems that fire magic at you?
Remove the gem from its pedestal by magic, throwing things at it or simply picking it up.

You can use sneak.Some skills at sneak can make you invisible to traps.Also you can just make your character stronger until he have enough health to get the gem.

when i get there the soul gem is lying on the floor not on the pedestal

Jump over it?

If this is the location I'm thinking of, I walked around it to the left on some rocks instead of following the path and it didn't go off.

Fire Breath works every time for me....

Shooting the soul gem with an arrow worked for me, though it seemed to take a few tries.

On a related note, does anybody know exactly how much damage these things do? The first time I tried to disable it, I walked around the side of it and grabbed the soul gem. However, it got a spell out (Ice Storm) a split second before I grabbed it. My character (level 33, master difficulty, 380 life, no resistances) died instantly. That's odd, because I'm pretty sure a single adept-level spell shouldn't be capable of doing 400 damage (or 200, since master difficulty doubles damage). I was pretty shocked that I died from something like that.

Edit: Coincidentally, my Breton was the same level, so I took him over to the trap to see what it did to him. It knocked him from 320 to 227 HP, and he has max (80%) magic resistance (and no frost resistance). So I guess it does about 230 base damage, or about 460 to a person on master without any resists. So this trap does about twice as much damage as my Breton's perked dual-casted Ice Storm, not including difficulty bonuses. That's not very cool.

Edit: So it's pretty much equal to the maximum damage the player could ever possibly do. Perks, dual-casted, then double damage from alchemy buffs.

Those traps are extremely deadly. Fireball is a good way to dislodge them.

If you have the Become Ethereal shout, you should always use that whenever you're confronted with a difficult trap. As long as the shout is active and you don't attack anyone or anything, you'll be invincible.

For Soul Gem traps, then, just rush the gem while in ethereal form and take it.

For rune traps, just activate the rune by stepping on it while the shout is active.

This.
I have found this approach immensely useful for dealing with the pesky soul-gem traps.
Don't understand how in the world a soul gem throwing ice around is able to almost 1/2 health my magic-resisant mage- nord when I actually just try to run up and grab it without the shout. Its bonkers if you ask me

I shout at it. Fire or Frost Breath

What part of the rune trap will I shoot with arrow to disable it???

i think i know what location OP is talking about. this gem trap will still fire even after the soul gem is removed. very annoying. but every other gem trap i've come across have worked properly, this one is definitely bugged though.

Remember, difficulty increases the damage dealt by enemies by a huge factor. At master it's like x6.. x8 damage I think. While a player might only cast a spell for 60 damage, an enemy casting the same spell is going to hit for like 300-400 damage - walking around with no spell resistance when mages are around is as fatal as walking about with no armour on in a knife fight

I always use arrows to dislodge the soul gems. I've never had a problem with it.

The OP is not talking generally about soul traps, but about one in particular. It fires an Ice storm at you even without a gem in it.

You'll either have to use slow time or ww sprint. Or, do what I did and make a PITA climb up the other side.

Cast Conjure Familiar on it.

Ice Spike works for me.

That one is fairly easy. As one poster said, just go into sneak mode and walk around the stone wall to the left and walk right by it. You can even then, walk up to it from the side and remove it. Can't speak to the going off with the soul stone removed as that's never happened to me in several tries.

a direct HIT with an arrow or a fireball spell works.. so does unrelenting force!