PCA tank design tables
PCA tank design tables
(OP)
Does anybody knows why in PCA tables for rectangular tank design example,the calculation do not take into account Mxy( twisting) moment in addition to Mx moment (wood Armer equations)while calculating final design moment/coeff. for vertical steel?
Same is true for horz. steel.
The only place Mxy moments are used is while designing top "simply supported" slab.
The tank tables in section 3 which include effect of wall/frame stiffness for rectangular configuration do include table for Mxy values.
Same is true for horz. steel.
The only place Mxy moments are used is while designing top "simply supported" slab.
The tank tables in section 3 which include effect of wall/frame stiffness for rectangular configuration do include table for Mxy values.






RE: PCA tank design tables
Thanks,
FEM4Structures
RE: PCA tank design tables
Adding Mx and My in concrete design - or using their resultant - doesn't make any sense.
RE: PCA tank design tables
I think LOKSTR is talking about the twisting or torsional moments that are encountered at the corners and other supports of slabs (and walls). Those moments do have to be added in some way to the Mx and My moments, and there are various methods of doing this. Using computers, some programs do it automatically, some make it an option, and some ignore the twisting, which is not correct.
There are a variety of threads on the site about this topic, mostly for flat slabs and flat plates.
RE: PCA tank design tables
I was responding to the idea of using the resultant of Mx and My in design of concrete - which we at least never do.
RE: PCA tank design tables
Thanks. I am using Mx+Mxy and My+Mxy in my spreadsheets using the values taken from PCA table for particular b/a and c/a ratio,
but I am not sure why in the example given in "PCA rectangular Concrete tanks 5th edition" the author do not show the addition of Mx and Mxy in the sample calculation for vertical and horizontal steel for long side and short side of tank.
In the example he ignored Mxy totally.
RE: PCA tank design tables