Hello,

I have few queries related to community hall without internal columns, my attached staad file

1. Main beam is of 17.27m length with size 450X725mm. This continuous beam is shown as passed even though L/d ratio is not meeting however it is satisfying the deflection criteria of L/250 as per IS 456. Also, the same beam in RC design showing failed in L/d ratio. Kindly let me know that Staad doesn't account for L/d ratio while designing. Most of the engineers will depend only on staad output for design.

2. To avoid one way slab I had included secondary beams(spanning in 16.77m length) without intermediate column supports and made to connect with primary beams. These secondary beams are shown as passed with beam size of 230X425mm itself, but the moment behavior is shown as continuous beam with negative moment at end supports and positive moment at mid span of 16.77m. I am confused with the moment behavior, L/d ratio and rebar detailing. Please clarify.

3. Short length beams (#69,99) are failing while designing. I had tried increasing depth and using SFACE command but of no use. Technically this beam (11.32m length) size cannot be more than 17.27m beam size. Please provide to overcome this issue.

I had attached staad file for your pursuant

.communities.bentley.com/.../RCH1.std