Hello,
I have a slab supported by pile caps as well as columns and walls due to having to drop some pile caps. This is a situation I have not dealt before when it come to laying out design strips.
Please let me know if my approach and settings are sensible. I have uploaded my model using the Secure File Upload Tool.
Here are some tips for design strip layout, including drop panels. https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/4507/ram-concept-design-strips-tn
In your case, it looks like you have dedicated span segments for the larger drop panels which is fine, but some of the strips are either very short or extending in a wide direction too far. I circled some of the odd looking spans.
Use span boundary polylines and column strip boundary polylines to control the width of strips.
Hi Seth, I did not do any span boundaries yet, as I was not sure if the actual layout of the spans makes sense. I am wondering what is best:
1.
2. With Slab Rectangle Cross-section trimming.
3. Some variation of 2
4. Are these settings correct?
For a stiff drop panel I don't see any problem stopping at the face of the panel. You could snap to the center of the panel instead, and then provide a large support width so that the first section is beyond the face of the panel, treating it like a large column. That's effectively the same thing, but works better for sequential span numbering and total span length determination.
I'm a little worried about tiny strips between the piles, your image 2, because there won't be very many elements in this tight area. Using design sections there might be simpler.
Of course, never model orthogonal design strips on the same layer.
I have them on separate layers, just showing both on this image. Do you have any comments on 4? If not thanks for your comments; I will start putting in my span boundary polylines.
If you are stopping at the face of the panel, then yes, that ought to be considered as a support with dimension 0 (or very small).
Answer Verified By: Asen Filkov
Would you also consider both of the "free ends" as 0 mm width supports or have that box unchecked for one/both spans? I am wondering the same thing with the beams at the edge: should both strips be considered as being supported at the ends where they meet? I am struggling to understand when you would untick that box.
I can't tell from the image what the end away from the drop panel is. If it's a column or pile then it's also a support.
Free edges are not supports. Segmented spans that have points in the span that are not supports too.