Dear scaffolders, hello.
I have a question for scaffold designers who design falsework towers according to european code EN 12812 ("Falsework - performance requirements and general design"). The question is regarding chapter 9.3 - Imperfections and boundary conditions.
In my opinion there are very confusing instructions regarding how to model a tower taking into consideration all possible imperfections. There are listed: sway imperfections, bow imperfections, angular imperfections at spigot joints, imperfections for single tubes, imperfections for entire tower, local imperfections, global imperfections..
I have some ideas how to model all this, but I am afraid not to overcomplicate the problem (which I definitely do, if I make few models for every single tower and every single member within a tower). I have asked some other scaffold designers, and none can tell me for sure how to approach the problem.
How do you model following towers, taking imperfections into consideration:
1. prefabricated towers (like Doka or Peri or Layher or Noe..) built by adding upper unit on top of lower unit. I know there are method statements that every producer of towers has, in which there are instructions regarding structural design, but what when there is an atypical problem (for example you want to examine load resistance of a tower erected higher than a method statement describes).
2. towers made out of steel profiles (I-profiles, RHS, CHS, tie members..) that one must design from a scratch. How do you model imperfections then?
3. towers made out of loose tubes, joined by couplers and/or spigots?
These are very important questions to be resolved and discussed. Resolving them will bring priceless information for us all, scaffold designers. I have an idea to properly "digest" this code (EN 12812), so we can bring our competences to a higher level.
Friendly greetings,
Milan Atanackovic
I have a question for scaffold designers who design falsework towers according to european code EN 12812 ("Falsework - performance requirements and general design"). The question is regarding chapter 9.3 - Imperfections and boundary conditions.
In my opinion there are very confusing instructions regarding how to model a tower taking into consideration all possible imperfections. There are listed: sway imperfections, bow imperfections, angular imperfections at spigot joints, imperfections for single tubes, imperfections for entire tower, local imperfections, global imperfections..
I have some ideas how to model all this, but I am afraid not to overcomplicate the problem (which I definitely do, if I make few models for every single tower and every single member within a tower). I have asked some other scaffold designers, and none can tell me for sure how to approach the problem.
How do you model following towers, taking imperfections into consideration:
1. prefabricated towers (like Doka or Peri or Layher or Noe..) built by adding upper unit on top of lower unit. I know there are method statements that every producer of towers has, in which there are instructions regarding structural design, but what when there is an atypical problem (for example you want to examine load resistance of a tower erected higher than a method statement describes).
2. towers made out of steel profiles (I-profiles, RHS, CHS, tie members..) that one must design from a scratch. How do you model imperfections then?
3. towers made out of loose tubes, joined by couplers and/or spigots?
These are very important questions to be resolved and discussed. Resolving them will bring priceless information for us all, scaffold designers. I have an idea to properly "digest" this code (EN 12812), so we can bring our competences to a higher level.
Friendly greetings,
Milan Atanackovic