DESIGNING A SLAB WITH A OPENING & MOVING LOADS

[Noopur]

Hello everybody,
I would like to model a concrete slab (15" thick) with an opening. Also the slab is subjected to moving loads (wheel loads). Can anyone suggest me the best way to do this?

I am trying this:
1. Modeling it as plate elements (15" thickness)with a opening & simply supported at all four sides. In that case I don't know how to use moving load option (I think I can't).

2. Modeling it as beams on all four sides of the slab and also on all four edges of the opening (length of beams being the same as the slab length/or width). I will be having total eight beams. In that case I can use the moving load option of STAAD. But...will this model represents the actual slab???

I am using STAAD-Pro. The slab is actually lid of a manhole. The opening is for placing the grate. So....actually the wheel load can be placed on opening (grate) too!

Sorry for making it long. my intention was to make it clear.

Thanks in advance.

 

[edward1]

Noopur, If the cover plate is at or near the center of slab,
you can take the maximum wheel load and distribute it equally on the cover plate support points of slab. Then all
you need to do is model the concrete slab with the opening
for the cover plate. I model the supports of the slab as pinned joints. This gives conservative results since you aren't including the cover plate. Be sure to add the weight
of cover plate and selfweight of slab to loads.