Any standards for designs using live trees?
Any standards for designs using live trees?
(OP)
Does anyone know of any standards for using live trees in the design of a structure which carries people? It is for a zipline that would be used to carry one person at a time. I would recommend that the tree be load tested to 1.5-2 times the design load, but I don't think that is enough. There is just not a good way to be able to model a trees root system. Any suggestions would be appreciated.
"Structural engineering is the art of modeling materials we do not wholly understand into shapes we cannot precisely analyse so as to withstand forces we cannot properly assess in such a way that the public at large has no reason to suspect the extent of our ignorance." -Dr. A. R. Dykes






RE: Any standards for designs using live trees?
Please - no deadman jokes here...
Mike McCann
MMC Engineering
RE: Any standards for designs using live trees?
BA
RE: Any standards for designs using live trees?
I would suggest that a factor of safety in the 1.5 to 2.0 range would be inadequate. Minimum I would consider for using a tree (or for that matter any elevated amusement device) would be 5.0 or higher (similar to suspended work platforms). There is also the concept of two independent means of support which should be considered.
Msquared's idea of using a deadman anchor is also a good idea for consideration.
RE: Any standards for designs using live trees?
RE: Any standards for designs using live trees?
Thanks, that is one option I've considered. The issue is that access is tough for pouring concrete and one option I am considering is using guy wires tied to boulders that can be set and placed behind the tree. Even with the guy wires the problem is that it becomes a matter of compression on the tree, which I do not have a standard to design to. I've thought of just using a conservative compressive strength value?
"Structural engineering is the art of modeling materials we do not wholly understand into shapes we cannot precisely analyse so as to withstand forces we cannot properly assess in such a way that the public at large has no reason to suspect the extent of our ignorance." -Dr. A. R. Dykes
RE: Any standards for designs using live trees?
Or maybe it would be better to abandon the tree altogether and erect a guyed tower.
BA
RE: Any standards for designs using live trees?
Thanks, I will check out the TSSA link. The standards that are out there are from the ACCT (www.acctinfo.org) and the PRCA (www.prcainfo.org), and no this is not the rodeo association. I have both of these and have reviewed them. There is not any real guidance on these as far as design with live trees.
As far as factors of safety, yes I was planning on 5. In the initial post, I was only referring to load testing the tree at 1.5-2 of the design load.
"Structural engineering is the art of modeling materials we do not wholly understand into shapes we cannot precisely analyse so as to withstand forces we cannot properly assess in such a way that the public at large has no reason to suspect the extent of our ignorance." -Dr. A. R. Dykes
RE: Any standards for designs using live trees?
I will look at the 3 guys idea, I think that would help. I would love to just use a guyed tower.
"Structural engineering is the art of modeling materials we do not wholly understand into shapes we cannot precisely analyse so as to withstand forces we cannot properly assess in such a way that the public at large has no reason to suspect the extent of our ignorance." -Dr. A. R. Dykes
RE: Any standards for designs using live trees?
Mike McCann
MMC Engineering
RE: Any standards for designs using live trees?
Mike McCann
MMC Engineering