11-11-2010, 09:52 AM
It will be useless to check the stability without any real data for your structure, but only using some literature and advices (it could be illegal, depending of the regulations).
My advices (except of testing) are:
Do not include cohesion at all, as the structure is not monolithic. So at zero stress - "zero strength". No tension of course!
The weak planes are the contacts between the blocks, so check only them. Check only sliding through these contacts and the base.
Check overturning safety at the base, and at each contact (you don't need the contact strength.
Include water penetrating the contact!
Don't forget the wave action!
The friction angle depends on the surface smoothness and the aggregate material of the concrete. Usually testing gives values between broad range - 30~50 degrees. The lower is for high paste concrete. I expect that during the years and the water abrasion there should be some "penetration" of the surfaces, with washing of the fine material, and leaving the coarse aggregate "interlocked". But the actual strength depends on the contact surface, the aggregate shape and its bond-strength with the paste.
If it is impossible (whatever reason) to test the blocks, then do a back calculation - to find what friction between blocks is enough to keep the wall still standing on water, waves, some other forces, which you should know better than me. Then if the necessary friction is very low - (i.e. below 35 degrees) - it seems the wall should be safe.
My advices (except of testing) are:
Do not include cohesion at all, as the structure is not monolithic. So at zero stress - "zero strength". No tension of course!
The weak planes are the contacts between the blocks, so check only them. Check only sliding through these contacts and the base.
Check overturning safety at the base, and at each contact (you don't need the contact strength.
Include water penetrating the contact!
Don't forget the wave action!
The friction angle depends on the surface smoothness and the aggregate material of the concrete. Usually testing gives values between broad range - 30~50 degrees. The lower is for high paste concrete. I expect that during the years and the water abrasion there should be some "penetration" of the surfaces, with washing of the fine material, and leaving the coarse aggregate "interlocked". But the actual strength depends on the contact surface, the aggregate shape and its bond-strength with the paste.
If it is impossible (whatever reason) to test the blocks, then do a back calculation - to find what friction between blocks is enough to keep the wall still standing on water, waves, some other forces, which you should know better than me. Then if the necessary friction is very low - (i.e. below 35 degrees) - it seems the wall should be safe.