Close to edge fixing in block wall.

I wish to fix a 125mm x 100mm fence post to the top of a concrete block retaining wall. The post is 2.7meters long and about 750mm is available for fixing. The difficulty is the wall. It is twin skin. The inner skin is concrete blocks on their side and is 21cm thick. The outer skin is concrete blocks on end and is 10cm thick. The two are tied together at intervals with butterfly ties and there is a 2.5cm gap between the two. Add to that, the fixings will be no more than 7-8cm from the free edge of the wall. I'm not sure what to do. There is no access to the back of the wall. Resin studs seem a possibility. They are expensive and I am thinking the resin could trickle away down the gap between the skins, but I have no experience with this type of fixing. I'm worried throughbolts might pull the two skins together and crack the wall, and conventional expanding bolts may blow out the blocks so close to the edge? I do have the option of using a 3.6meter post which would stand on the footing of the wall. this would allow lighter fixings to the wall itself. Sorry for the wordy description, any advice greatly appreciated!

Ralph - what's going to be the function of this fence post and what type of load is it going to be sujected to? Close-boarded fence, ranch style fence, deer netting, fruit netting ... different wind resisting characteristics and therefore loading. This will determine fixing method.

Hi Symptoms, the post will be one end of a 3 meter length of 1.8meter high close boarded feather edge panel. This is a fairly windy spot high in the Chilterns, so forces will be considerable at times.

Go with the posts right down to the ground, resin or thrubolt into the wall, pour some lean mix concrete down the gap between the walls, behind each post.

Yup, that is what I will do. Thank you!