All,
I'm in the process of designing concrete buttresses (hopefully in RAM SS/Concrete) to help with deflection issues in existing concrete columns. The existing building has concrete walls that infill between the columns. I have several questions:
-I understand that when a wall is connected to a column, they become integrally connected. Is there a way for the column to transfer lateral forces only (ie the existing column will lean on the buttress but not transfer moment)
-The reactions that I am getting are at 3 different locations. There are 2 nodal reactions at each column/buttress location (one at the base of the column and one at the end of the wall). In addition, if you cut a section at the base of the shear wall, there appears to be reactions for a fixed base (moment, shear, axial). I haven't been able to resolve the reactions with the applied loads. Is there any description or guidance on how these reactions are calculated and what they mean?
-is there any way to rotate the orientation of a steel beam? I plan on using like a W30 on it's side to transfer the lateral forces from the interior columns to the buttresses.
-I keep getting an error that a column offset has failed. The intent was that the base of the existing concrete columns is 4'3 wide and at the one end there is a 24" deep column that is flush. Has this been encountered before?
Lastly, is there a way to research for issues only associated within the various programs (RAM elements, RAM SS, Staad, etc?) It seems to me that while they overlap, many times I find it hard to find the answer for a specific program because there is so much information on other programs.
Thanks
Ryan
The column and wall will be linked and the column will be a continuous member through the height of the story, so there is moment fixity at the nodes of the finite element mesh between the stories. There is no way to suppress that, but you can pin the column at the stories and would not expect much moment in the columns to transfer to the walls.
You should be getting reactions at the base level only. You can plot reactions at the mesh points, or limit the output to just the major nodes using Process - Results - Reactions - and the toggle for "Show reactions at all nodes". At each node, reactions are possible in all 6 degrees of freedom, but again I would expect the in-plane translational reactions to be the significant ones (Ry, Rz).
If you are getting reactions at higher levels then something is not connected as you intend and the program is introducing an unintended support. This could relate to the use of offsets you mentioned. If you are having a problem try modeling each column at it's own centroid location and then model a stub-cantilever beam where necessary to transfer from one CL to another. The rigid links we use internally are essentially just stiff stub cantilevers anyway.
You cannot rotate beams in RAM SS, our tables wiki mentions some work-around for that.
Within Communities search you can search by Tags (use the Advanced Search link that appear bottom right of the quick search results) and filter things fairly well. Not all posts are tagged, so you can also just add the product into your search string.