Slab design in staad pro.

Question

Hello I'm just a beginner in staad pro. I'm trying to design a 6-storey building. After analyzing the structure i used commands option to perform concrete design. It gave me reinforcing details for column and beam. But not for slab. I added plates for slabs and perform quadrilateral surface meshing.(I read that in a tutorial I don't even know what surface meshing is) My questions are: 
 1) What should I do to design slab? 2) Can i perform calculation of lift and stairs in staad pro? if so then how? Please take a look at my file and point out any error. 
 Thanks and appreciation in advance for help.

Surojit Ghosh · Accepted Answer

Hi, 
 It is because, minimum reinforcement governs in this case. The moments on the slab are too small to warrant any steel requirement to resist flexure. As the minimum steel is adequate, so program displays a message as: 
 478 TOP : Longitudinal direction - Only minimum steel required. 
 Minimum steel percentage is based on Clause 7.12.2.1 of ACI 318. If you increase the loading, reinforcement percentage will increase accordingly. 
 If the plate is finely meshed, then there will be more number of internal nodes for which the program calculates the displacement and stress values. A fine mesh will always have better results, but will simultaneously increase the run time and the volume of data. So, the mesh size should be based on an optimization between the accuracy required and the run time.

Surojit Ghosh · Answer

Hi, 
 To design a concrete slab in STAAD.Pro, you need to add the DESIGN ELEMENT command. In your model, you have specified the command and program designs all the plate elements. The reinforcement details are reported in the output file as shown in the following figure:

Surojit Ghosh · Answer

There might be several reasons for this and to answer it properly, I need to investigate the model, Can you upload your STAAD model and also mention the build number of STAAD that you are using?