jackyyau
Civil/Environmental
- May 13, 2002
- 38
Plate sub-model, your views?
I have an underground reinforced concrete box station 16.5m wide by 35m deep by 280m long modelled by plane frame with SAP2000. The frame is 16.5m wide and 35m deep. The model is as follows:
roof
|--------|
| |
| slab1 |
|--------|
| |
W| |
A| slab2 |
L|--------|
L| |
| slab3 |
|--------|
| |
| slab4 |
|--------|
| |
" "
After loading the frame with all the vertical dead, superimposed loads, horizontal water and soil pressures and getting the moment, shear and displacement outputs, I continue to develope local models for the slabs because the slabs have many openings (holes) for escalators, lifts and E&M vent shafts.
I modelled the slab by shell elements. But I have quesions on the ways to model the support condition and the loadings on the slab. Should model the support condition (assume the boundary nodes to be fixed) and put the vertical loads on the slab and horizontal loads on the supports?
nodes fixed
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| ------ --------- }
| | hole | | hole | }
| ------ --------- }
| }
| }
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nodes fixed (how long to model?)
What is the length of the slad should be modelled? 3m from either side of the hole or 3 times slab thickness?
The loads applied on the fixed nodes have no effect on the slab as the supports take up the loads directly!!!
Should I load the slab with those outputs from the frame model, and how? (bear in mind that we cannot load the supports!!)
