CSA A23.3 Concrete Wall Design

[Shotzie]

Hello,

As my previous post explained Link, the Canadian company I work at will soon be getting into mid-rise concrete building projects. I’m involved with making a software selection for the company in order to assist us with the design of these projects. I’ve done some pretty extensive research on RISA (3D, Floor ES, Foundation), which has seemed quite promising. My concern is the lack of CSA A23.3 code support for concrete wall design (gravity and lateral). After speaking with someone at RISA I’ve confirmed concrete wall design to CSA A23.3 will be supported in RISA Floor v13 and RISA 3D v17. It seems like foundations, columns, beams, and slabs can all be done as per Canadian code currently which is a perk. I’m curious how the Canadian engineers who have RISA deal with this? Do you ensure the reinforcement/wall thickness is correct to determine the loads in the walls then design using spreadsheets? The other software option we’re considering is the CSI America programs (ETABS, SAP2000, SAFE) due to their Canadian code support.

Thanks

 

[jayrod12]

We use RISA extensively here and perform wall design exactly as you indicate. Use the program for the analysis and then spreadsheets for the design. It seems to work pretty rosy for now. Can't wait for them to include wall design for the Canadian users.

 

[dik]

When I've used RISA, I've used it for analysis, only... and excellent tool... for design, I'm a bit of a dinosaur... I use excel spreadsheets for steel or concrete.

Dik

 

[Shotzie]

Thanks for the input jayrod12 and dik, I was hoping you guys would chime in. For your spreadsheets, do they typically handle strength checks to get reinforcement requirements only? Or do you do serviceability checks in the spreadsheets as well, as opposed to leaving drift/deflection calculations and checks up to RISA? I imagine it can get quite convoluted when you have a slab deflecting relative to a beam, etc.

 

[dik]

I take a look at the force outputs from Risa and see if they make sense I may do a quick fixed end for an interior span or a ql2/16 for an end span -ve or maybe a ql2/11 or 12 for an endspan +ve... or whatever I feel like that day and if Risa's output is approx... I assume the balance of Risa's output is more or less correct... I take a serious look at support condition moments... shears a little less arbitrary, and axial loads quite carefully... I may 'meatball' a calc, except for compression elements... it's a good check...

I then use spreadsheets for design in concrete or steel or a couple of programs I wrote in Delphi... conc columns, walls, interaction diagrams and biaxial bending...Other than support conditions, and they depend on how I model them, I have 100% confidence in Risa's output.

Dik

 

[jayrod12]

Serviceability checks are rarely a concern for concrete walls in my projects. If you are talking drift, then I generally rely on Risa's output but I've checked it by hand a few times and am confident the approach is sound.

 

[P205]

I'm surprised that no one chimed in for ETABS. Most of my experience (at previous company) is with ETABS but mostly for steel framed buildings. Now at my current company we have Risa3D. No RisaFloor, which I realize is pretty crucial for multi storey buildings. I haven't used it seriously for 3D modelling yet.

Anyway, Shotzie, did you end up making a decision on which way to go? From my research, it seems that there is much more help/resources around for Risa3D. Maybe I just haven't found where all the ETABS users are hiding on the internet.

 

[Shotzie]

@stiman86 The lack of ETABS responses was probably influenced by the forum I posted this in, if I had to guess. Our office ended up selecting ETABS paired with the eventual purchase of SAFE (no SAP2000) for now to do midrise concrete and steel buildings. This was mostly influenced by having a third party peer reviewer who works primarily with ETABS, we are able to compare models and discuss design, analysis, and modelling procedures much more easily since we're working with the same program. I definitely agree that there is a lot of useful resources online regarding the RISA software, and the help documents are really well written. I haven't seen quite the same level of support or documentation online for ETABS. I also don't believe anyone from our office has reached out with technical support questions to CSI America yet.

I believe we will end up purchasing some RISA programs, but the focus of those would be for miscellaneous wood structures, such as timberframes, and potentially using them for midrise wood structures.

 

[P205]

Thanks for the update.

I just remembered that I did do a multi-storey building with concrete shear walls, and what the majority of people at our office would do (and what I was taught) was to copy/paste the output from ETABS into S-Concrete for each wall. Not sure if you've used S-Concrete but it's excellent for checking hundreds of load cases and it has a great user interface that allows for quickly trying out different reinforcement options.

 

[Shotzie]

@stiman86 No problem. Thanks for the suggestion, I haven't used that program but I do remember that some people in the office were looking into it. We're still in the layout/analysis phase so we haven't gotten into designing the beams/columns/slabs/walls. I assumed I would be spending a few weekends making spreadsheets but I'll check out that program, could be a good time saver or a supplement to the spreadsheets.